atom feed11 messages in com.xensource.lists.xen-devel[Xen-devel] [PATCH 2/9] dm-ioband-1.1...
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Ryo TsurutaSep 14, 2009 5:27 am 
Ryo TsurutaSep 14, 2009 5:28 am 
Ryo TsurutaSep 14, 2009 5:28 am 
Ryo TsurutaSep 14, 2009 5:29 am 
Ryo TsurutaSep 14, 2009 5:29 am 
Ryo TsurutaSep 14, 2009 5:30 am 
Ryo TsurutaSep 14, 2009 5:30 am 
Ryo TsurutaSep 14, 2009 5:31 am 
Ryo TsurutaSep 14, 2009 5:31 am 
Daniel WalkerSep 14, 2009 7:10 am 
Ryo TsurutaSep 14, 2009 8:06 am 
Subject:[Xen-devel] [PATCH 2/9] dm-ioband-1.13.0: All-in-one patch
From:Ryo Tsuruta (ry@valinux.co.jp)
Date:Sep 14, 2009 5:28:16 am
List:com.xensource.lists.xen-devel

The body of dm-ioband. This patch is an all-in-one patch of dm-ioband so that it replaces dm-add-ioband.patch in the device-mapper development tree.

Signed-off-by: Ryo Tsuruta <ry@valinux.co.jp> Signed-off-by: Hirokazu Takahashi <ta@valinux.co.jp>

--- Documentation/device-mapper/ioband.txt | 1113 +++++++++++++++++++++++++ Documentation/device-mapper/range-bw.txt | 99 ++ drivers/md/Kconfig | 13 drivers/md/Makefile | 3 drivers/md/dm-ioband-ctl.c | 1357 +++++++++++++++++++++++++++++++ drivers/md/dm-ioband-policy.c | 543 ++++++++++++ drivers/md/dm-ioband-rangebw.c | 669 +++++++++++++++ drivers/md/dm-ioband-type.c | 76 + drivers/md/dm-ioband.h | 231 +++++ include/trace/events/dm-ioband.h | 242 +++++ 10 files changed, 4346 insertions(+)

Index: linux-2.6.31/Documentation/device-mapper/ioband.txt =================================================================== --- /dev/null +++ linux-2.6.31/Documentation/device-mapper/ioband.txt @@ -0,0 +1,1113 @@ + Block I/O bandwidth control: dm-ioband + + ------------------------------------------------------- + + Table of Contents + + [1]What's dm-ioband all about? + + [2]Differences from the CFQ I/O scheduler + + [3]How dm-ioband works. + + [4]Setup and Installation + + [5]Getting started + + [6]Command Reference + + [7]Examples + +What's dm-ioband all about? + + dm-ioband is an I/O bandwidth controller implemented as a device-mapper + driver. Several jobs using the same block device have to share the + bandwidth of the device. dm-ioband gives bandwidth to each job according + to bandwidth control policies. + + A job is a group of processes with the same pid or pgrp or uid or a + virtual machine such as KVM or Xen. A job can also be a cgroup by applying + the blkio-cgroup patch, which can be found at + http://sourceforge.net/apps/trac/ioband/. + + +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ + |cgroup | |cgroup | | the | | pid | | pid | | the | jobs + | A | | B | |others | | X | | Y | |others | + +---|---+ +---|---+ +---|---+ +---|---+ +---|---+ +---|---+ + | | | | | | + +-----|---------|---------|----+----|---------|---------|-----+ + | | /dev/mapper/disk1 | | | /dev/mapper/disk2 | | + |-----|---------|---------|----+----|---------|---------|-----| + | +---V---+ +---V---+ +---V---+ +---V---+ +---V---+ +---V---+ | + | | ioband| | ioband| |default| | ioband| | ioband| |default| | + | | group | | group | | group | | group | | group | | group | | dm-ioband + | |-------+-+-------+-+-------+-+-------+-+-------+-+-------| | + | | bandwidth control | | + | +-------------|-----------------------------|-------------+ | + ---------------|-----------------------------|--------------- + | | + +---------------V--------------+--------------V---------------+ + | /dev/sdb1 | /dev/sdb2 | partitions + +------------------------------+------------------------------+ + + + -------------------------------------------------------------------------- + +Differences from the CFQ I/O scheduler + + Dm-ioband is flexible to configure the bandwidth settings. + + Dm-ioband can work with any type of I/O scheduler such as the NOOP + scheduler, which is often chosen for high-end storages, since it is + implemented outside the I/O scheduling layer. It allows both of partition + based bandwidth control and job --- a group of processes --- based + control. In addition, it can set different configuration on each block + device to control its bandwidth. + + Meanwhile the current implementation of the CFQ scheduler has 8 IO + priority levels and all jobs whose processes have the same IO priority + share the bandwidth assigned to this level between them. And IO priority + is an attribute of a process, so that it equally effects to all block + devices. + + -------------------------------------------------------------------------- + +How dm-ioband works. + + The bandwidth of each job is determined by a bandwidth control policy. + dm-ioband provides three kinds of policies "weight", "weight-iosize" and + "range-bw", and a user can select one of them at the time of setup. + + -------------------------------------------------------------------------- + + weight and weight-iosize policy + + Every ioband device has one ioband group, which by default is called the + default group, and can also have extra ioband groups in the ioband device. + Each ioband group has its own weight and tokens. The amount of tokens are + determined proportional to the weight of each ioband group. + + The ioband group can pass on I/O requests that its job issues to the + underlying layer so long as it has tokens left, while requests are blocked + if there aren't any tokens left in the ioband group. The tokens are + refilled once all of the ioband groups that have requests on a given + underlying block device use up their tokens. + + The weight policy lets dm-ioband consume one token per one I/O request. + The weight-iosize policy lets dm-ioband consume one token per one I/O + sector, for example, one I/O request which consists of 4Kbytes (512bytes * + 8 sectors) read consumes 8 tokens. + + With this approach, a job running on the ioband group with large weight + is guaranteed a wide I/O bandwidth. + + -------------------------------------------------------------------------- + + range-bw policy + + range-bw means the predicable I/O bandwidth with minimum and maximum + value defined by administrator. And it is also possible to set up only + maximum value for only I/O limitation. So, you can define the specific and + fixed bandwidth to satisfy I/O requirement regardless of whole I/O + bandwidth. + + Minimum I/O bandwidth is to guarantee the stable performance or + reliability of specific process group and maximum bandwidth is to throttle + the unnecessary I/O usage or to reserve the I/O bandwidth for another use. + So range-bw supports adequate and predicable I/O bandwidth between minimum + and maximum value. + + The setting unit is based on Kbytes/sec. If you want to allocate + 3M~5Mbytes/sec I/O bandwidth to X group, you should set 3000 to min-bw, + 5000 to max-bw. + + Attention + + Although range-bw supports the predicable I/O bandwidth, it should be + configured in the scope of total I/O bandwidth of the I/O system to + guarantee the minimum I/O requirement. For example, if total I/O bandwidth + is 40Mbytes/sec, the summary of I/O bandwidth configured in each process + group should be equal or smaller than 40Mbytes/sec. So, we need to check + total I/O bandwidth before set it up. + + -------------------------------------------------------------------------- + +Setup and Installation + + Build a kernel with these options enabled: + + CONFIG_MD + CONFIG_BLK_DEV_DM + CONFIG_DM_IOBAND + + + If compiled as module, use modprobe to load dm-ioband. + + # make modules + # make modules_install + # depmod -a + # modprobe dm-ioband + + + "dmsetup targets" command shows all available device-mapper targets. + "ioband" and the version number are displayed when dm-ioband has been + loaded. + + # dmsetup targets | grep ioband + ioband v1.0.0 + + + -------------------------------------------------------------------------- + +Getting started + + The following is a brief description how to control the I/O bandwidth of + disks. In this description, we'll take one disk with two partitions as an + example target. + + -------------------------------------------------------------------------- + + Create and map ioband devices + + Create two ioband devices "ioband1" and "ioband2". "ioband1" is mapped + to "/dev/sda1" and has a weight of 40. "ioband2" is mapped to "/dev/sda2" + and has a weight of 10. "ioband1" can use 80% --- 40/(40+10)*100 --- of + the bandwidth of "/dev/sda" while "ioband2" can use 20%. + + # echo "0 $(blockdev --getsize /dev/sda1) ioband /dev/sda1 1 0 0 none" \ + "weight 0 :40" | dmsetup create ioband1 + # echo "0 $(blockdev --getsize /dev/sda2) ioband /dev/sda2 1 0 0 none" \ + "weight 0 :10" | dmsetup create ioband2 + + + If the commands are successful then the device files + "/dev/mapper/ioband1" and "/dev/mapper/ioband2" will have been created. + + -------------------------------------------------------------------------- + + Additional bandwidth control + + In this example two extra ioband groups are created on "ioband1." + + First, set the ioband group type as user. Next, create two ioband groups + that have id 1000 and 2000. Then, give weights of 30 and 20 to the ioband + groups respectively. + + # dmsetup message ioband1 0 type user + # dmsetup message ioband1 0 attach 1000 + # dmsetup message ioband1 0 attach 2000 + # dmsetup message ioband1 0 weight 1000:30 + # dmsetup message ioband1 0 weight 2000:20 + + + Now the processes owned by uid 1000 can use 30% --- 30/(30+20+40+10)*100 + --- of the bandwidth of "/dev/sda" when the processes issue I/O requests + through "ioband1." The processes owned by uid 2000 can use 20% of the + bandwidth likewise. + + Table 1. Weight assignments + + +----------------------------------------------------------------+ + | ioband device | ioband group | ioband weight | + |---------------+--------------------------------+---------------| + | ioband1 | user id 1000 | 30 | + |---------------+--------------------------------+---------------| + | ioband1 | user id 2000 | 20 | + |---------------+--------------------------------+---------------| + | ioband1 | default group(the other users) | 40 | + |---------------+--------------------------------+---------------| + | ioband2 | default group | 10 | + +----------------------------------------------------------------+ + + -------------------------------------------------------------------------- + + Remove the ioband devices + + Remove the ioband devices when no longer used. + + # dmsetup remove ioband1 + # dmsetup remove ioband2 + + + -------------------------------------------------------------------------- + +Command Reference + + Create an ioband device + + SYNOPSIS + + dmsetup create IOBAND_DEVICE + + DESCRIPTION + + Create an ioband device with the given name IOBAND_DEVICE. + Generally, dmsetup reads a table from standard input. Each line of + the table specifies a single target and is of the form: + + start_sector num_sectors "ioband" device_file ioband_device_id \ + io_throttle io_limit ioband_group_type policy policy_args... + + + start_sector, num_sectors + + The sector range of the underlying device where + dm-ioband maps. + + ioband + + Specify the string "ioband" as a target type. + + device_file + + Underlying device name. + + ioband_device_id + + The ID for an ioband device can be symbolic, + numeric, or mixed. The same ID must be set among the + ioband devices that share the same bandwidth. This is + useful for grouping disk drives partitioned from one + disk drive such as RAID drive or LVM logical striped + volume. + + io_throttle + + When a device has a lot of tokens, and the number + of in-flight I/Os in dm-ioband exceeds io_throttle, + dm-ioband gives priority to the device and issues + I/Os to the device until no tokens of the device are + left. If 0 is specified, the default value is used. + This setting applies all ioband devices which has the + same ioband device ID as you specified by + "ioband_device_id." + + io_limit + + Dm-ioband blocks all I/O requests for IOBAND_DEVICE + when the number of BIOs in progress exceeds this + value. If 0 is specified, the default value is used. + This setting applies all ioband devices which has the + same ioband device ID as you specified by + "ioband_device_id." + + ioband_group_type + + Specify how to evaluate the ioband group ID. The + selectable group types are "none", "user", "gid", + "pid" or "pgrp." The type "cgroup" is enabled by + applying the blkio-cgroup patch. Specify "none" if + you don't need any ioband groups other than the + default ioband group. + + policy and policy_args + + Specify a bandwidth control policy. The selectable + policies are "weight", "weight-iosize" or "range-bw." + This setting applies all ioband devices which has the + same ioband device ID as you specified by + "ioband_device_id." + + policy_args are specific for each policy. See below + for information on each policy. + + WEIGHT AND WEIGHT-IOSIZE POLICIES + + The "weight" and "weight-iosize" policies distribute bandwidth + proportional to the weight of each ioband group. Each ioband group + is charged on an I/O count basis when the "weight" policy is used + and an I/O size basis when the "weight-iosize" policy is used. The + arguments are of the form: + + token_base :weight [ioband_group_id:weight...] + + + token_base + + The number of tokens which specified by token_base + will be distributed to all ioband groups proportional + to the weight of each ioband group. If 0 is + specified, the default value is used. This setting + applies all ioband devices which has the same ioband + device ID as you specified by "ioband_device_id." + + :weight + + Set the weight of the default ioband group. + + ioband_group_id:weight + + Create an extra ioband group with an + ioband_group_id and set its weight. The + ioband_group_id is an identification number and + corresponds to pid, pgrp , uid and so on which depend + on ioband group type settings. + + RANGE-BW POLICY + + The "range-bw" policy distributes the predicable bandwidth to + each group according to the values of minimum and maximum + bandwidth value. And range-bw is not based on I/O token which is + usually grant for I/O authority. + + So, "0" value is used for token_base parameter in range-bw + policy. And both parameters, min-bw and max-bw, are generally used + together, but, max-bw can be used alone for only limitation. The + arguments are of the form: + + token_base :min-bw:max-bw [ioband_group_id:min-bw:max-bw...] + + + token_base + + "0" is used, because it is not meaningful in this + policy + + min-bw + + Set the minimum bandwidth of the default ioband + group. This parameter can't be used alone. + + max-bw + + Set the maximum bandwidth of the default ioband + group. + + ioband_group_id:min-bw:max-bw + + Create an extra ioband group with an + ioband_group_id and set its min and max bandwidth. + The ioband_group_id is an identification number and + corresponds to pid, pgrp , uid and so on which depend + on ioband group type settings. + + EXAMPLE + + Create an ioband device with the following parameters: + + * Starting sector = "0" + + * The number of sectors = "$(blockdev --getsize /dev/sda1)" + + * Target type = "ioband" + + * Underlying device name = "/dev/sda1" + + * Ioband device ID = "share1" + + * I/O throttle = "10" + + * I/O limit = "400" + + * Ioband group type = "user" + + * Bandwidth control policy = "weight" + + * Token base = "2048" + + * Weight for the default ioband group = "100" + + * Weight for the ioband group 1000 = "80" + + * Weight for the ioband group 2000 = "20" + + * Ioband device name = "ioband1" + + # echo "0 $(blockdev --getsize /dev/sda1) ioband /dev/sda1" \ + "share1 10 400 user weight 2048 :100 1000:80 2000:20" \ + | dmsetup create ioband1 + + + Create two device groups (ID=1,2). The bandwidths of these + device groups will be individually controlled. + + # echo "0 $(blockdev --getsize /dev/sda1) ioband /dev/sda1 1" \ + "0 0 none weight 0 :80" | dmsetup create ioband1 + # echo "0 $(blockdev --getsize /dev/sda2) ioband /dev/sda2 1" \ + "0 0 none weight 0 :20" | dmsetup create ioband2 + # echo "0 $(blockdev --getsize /dev/sdb3) ioband /dev/sdb3 2" \ + "0 0 none weight 0 :60" | dmsetup create ioband3 + # echo "0 $(blockdev --getsize /dev/sdb4) ioband /dev/sdb4 2" \ + "0 0 none weight 0 :40" | dmsetup create ioband4 + + + -------------------------------------------------------------------------- + + Remove the ioband device + + SYNOPSIS + + dmsetup remove IOBAND_DEVICE + + DESCRIPTION + + Remove the specified ioband device IOBAND_DEVICE. All the band + groups attached to the ioband device are also removed + automatically. + + EXAMPLE + + Remove ioband device "ioband1." + + # dmsetup remove ioband1 + + + -------------------------------------------------------------------------- + + Set an ioband group type + + SYNOPSIS + + dmsetup message IOBAND_DEVICE 0 type TYPE + + DESCRIPTION + + Set an ioband group type of IOBAND_DEVICE. TYPE must be one of + "none", "user", "gid", "pid" or "pgrp." The type "cgroup" is + enabled by applying the blkio-cgroup patch. Once the type is set, + new ioband groups can be created on IOBAND_DEVICE. + + EXAMPLE + + Set the ioband group type of ioband device "ioband1" to "user." + + # dmsetup message ioband1 0 type user + + + -------------------------------------------------------------------------- + + Create an ioband group + + SYNOPSIS + + dmsetup message IOBAND_DEVICE 0 attach ID + + DESCRIPTION + + Create an ioband group and attach it to IOBAND_DEVICE. ID + specifies user-id, group-id, process-id or process-group-id + depending the ioband group type of IOBAND_DEVICE. + + EXAMPLE + + Create an ioband group which consists of all processes with + user-id 1000 and attach it to ioband device "ioband1." + + # dmsetup message ioband1 0 type user + # dmsetup message ioband1 0 attach 1000 + + + -------------------------------------------------------------------------- + + Detach the ioband group + + SYNOPSIS + + dmsetup message IOBAND_DEVICE 0 detach ID + + DESCRIPTION + + Detach the ioband group specified by ID from ioband device + IOBAND_DEVICE. + + EXAMPLE + + Detach the ioband group with ID "2000" from ioband device + "ioband2." + + # dmsetup message ioband2 0 detach 1000 + + + -------------------------------------------------------------------------- + + Set bandwidth control policy + + SYNOPSIS + + dmsetup message IOBAND_DEVICE 0 policy POLICY + + DESCRIPTION + + Set POLICY to a bandwidth control policy. The selectable + policies are "weight", "weight-iosize" and "range-bw." This + setting applies all ioband devices which has the same ioband + device ID as IOBAND_DEVICE. + + weight + + This policy distributes bandwidth proportional to + the weight of each ioband group. Each ioband group is + charged on an I/O count basis. + + weight-iosize + + This policy distributes bandwidth proportional to + the weight of each ioband group. Each ioband group is + charged on an I/O size basis. + + range-bw + + This policy guarantees minimum bandwidth and limits + maximum bandwidth for each ioband group. + + EXAMPLE + + Set bandwidth control policy of ioband devices which have the + same ioband device ID as "ioband1" to "weight-iosize." + + # dmsetup message ioband1 0 policy weight-iosize + + + -------------------------------------------------------------------------- + + Set the weight of an ioband group + + SYNOPSIS + + dmsetup message IOBAND_DEVICE 0 weight VAL + + dmsetup message IOBAND_DEVICE 0 weight ID:VAL + + DESCRIPTION + + Set the weight of the ioband group which belongs to + IOBAND_DEVICE. The group is determined by ID. If ID: is omitted, + the default ioband group is chosen. + + The following example means that "ioband1" can use 80% --- + 40/(40+10)*100 --- of the bandwidth of the underlying block device + while "ioband2" can use 20%. + + # dmsetup message ioband1 0 weight 40 + # dmsetup message ioband2 0 weight 10 + + + The following lines have the same effect as the above: + + # dmsetup message ioband1 0 weight 4 + # dmsetup message ioband2 0 weight 1 + + + VAL must be an integer larger than 0. The default value, which + is assigned to newly created ioband groups, is 100. + + EXAMPLE + + Set the weight of the default ioband group of "ioband1" to 40. + + # dmsetup message ioband1 0 weight 40 + + + Set the weight of the ioband group of "ioband1" with ID "1000" + to 10. + + # dmsetup message ioband1 0 weight 1000:10 + + + -------------------------------------------------------------------------- + + Set the range-bw of an ioband group + + SYNOPSIS + + dmsetup -- message IOBAND_DEVICE 0 range-bw -1:MIN:MAX + + dmsetup message IOBAND_DEVICE 0 range-bw ID:MIN-BW:MAX-BW + + DESCRIPTION + + Set the range-bw of the ioband group which belongs to + IOBAND_DEVICE. The group is determined by ID. If -1 is specified + as ID, the default ioband group is chosen. + + The following example means that "ioband1" can use + 5M~6Mbytes/sec bandwidth of the underlying block device while + "ioband2" can use 900K~1Mbytes/sec bandwidth. + + # dmsetup message -- ioband1 0 range-bw -1:5000:6000 + + # dmsetup message -- ioband2 0 range-bw -1:900:1000 + + + MIN-BW and MAX-BW and must be an integer larger than 0 and its + unit is Kbyte/sec. + + EXAMPLE + + Set the range-bw of the default ioband group of "ioband1" to + 200K~300K I/O bandwidth. + + # dmsetup -- message ioband1 0 range-bw -1:200:300 + + + Set the weight of the ioband group of "ioband1" with ID "1000" + to 10M~12M I/O bandwidth. + + # dmsetup message ioband1 0 range-bw 1000:10000:12000 + + + -------------------------------------------------------------------------- + + Set the number of tokens + + SYNOPSIS + + dmsetup message IOBAND_DEVICE 0 token VAL + + DESCRIPTION + + The number of tokens will be distributed to all ioband groups + proportional to the weight of each ioband group. If 0 is + specified, the default value is used. This setting applies all + ioband devices which has the same ioband device ID as + IOBAND_DEVICE + + EXAMPLE + + Set the number of tokens to 256. + + # dmsetup message ioband1 0 token 256 + + + -------------------------------------------------------------------------- + + Set a limit of how many tokens are carried over + + SYNOPSIS + + dmsetup message IOBAND_DEVICE 0 carryover VAL + + DESCRIPTION + + When dm-ioband tries to refill an ioband group with tokens after + another ioband group is already refilled several times, dm-ioband + determines the number of tokens to refill by multiplying the + number of tokens refilled once by the smaller of how many times + the other group is already refilled or this limit. If 0 is + specified, the default value is used. This setting applies all + ioband devices which has the same ioband device ID as + IOBAND_DEVICE. + + EXAMPLE + + Set a limit for "ioband1" to 2. + + # dmsetup message ioband1 0 carryover 2 + + + -------------------------------------------------------------------------- + + Set I/O throttling + + SYNOPSIS + + dmsetup message IOBAND_DEVICE 0 io_throttle VAL + + DESCRIPTION + + When a device has a lot of tokens, and the number of in-flight + I/Os in dm-ioband exceeds io_throttle, dm-ioband gives priority to + the device and issues I/Os to the device until no tokens of the + device are left. If 0 is specified, the default value is used. + This setting applies all ioband devices which has the same ioband + device ID as you specified by "ioband_device_id." + + EXAMPLE + + Set the I/O throttling value of "ioband1" to 16. + + # dmsetup message ioband1 0 io_throttle 16 + + + -------------------------------------------------------------------------- + + Set I/O limiting + + SYNOPSIS + + dmsetup message IOBAND_DEVICE 0 io_limit VAL + + DESCRIPTION + + Dm-ioband blocks all I/O requests for IOBAND_DEVICE when the + number of BIOs in progress exceeds this value. If 0 is specified, + the default value is used. This setting applies all ioband devices + which has the same ioband device ID as IOBAND_DEVICE. + + EXAMPLE + + Set the I/O limiting value of "ioband1" to 128. + + # dmsetup message ioband1 0 io_limit 128 + + + -------------------------------------------------------------------------- + + Display settings + + SYNOPSIS + + dmsetup table --target ioband + + DESCRIPTION + + Display the current table for the ioband device in a format. See + "dmsetup create" command for information on the table format. + + EXAMPLE + + The following output shows the current table of "ioband1." + + # dmsetup table --target ioband + ioband: 0 32129937 ioband1 8:29 128 10 400 user weight \ + 2048 :100 1000:80 2000:20 + + + -------------------------------------------------------------------------- + + Display Statistics + + SYNOPSIS + + dmsetup status --target ioband + + DESCRIPTION + + Display the statistics of all the ioband devices whose target + type is "ioband." + + The output format is as below. the first five columns shows: + + * ioband device name + + * logical start sector of the device (must be 0) + + * device size in sectors + + * target type (must be "ioband") + + * device group ID + + The remaining columns show the statistics of each ioband group + on the band device. Each group uses seven columns for its + statistics. + + * ioband group ID (-1 means default) + + * total read requests + + * delayed read requests + + * total read sectors + + * total write requests + + * delayed write requests + + * total write sectors + + EXAMPLE + + The following output shows the statistics of two ioband devices. + Ioband2 only has the default ioband group and ioband1 has three + (default, 1001, 1002) ioband groups. + + # dmsetup status + ioband2: 0 44371467 ioband 128 -1 143 90 424 122 78 352 + ioband1: 0 44371467 ioband 128 -1 223 172 408 211 136 600 1001 \ + 166 107 472 139 95 352 1002 211 146 520 210 147 504 + + + -------------------------------------------------------------------------- + + Reset status counter + + SYNOPSIS + + dmsetup message IOBAND_DEVICE 0 reset + + DESCRIPTION + + Reset the statistics of ioband device IOBAND_DEVICE. + + EXAMPLE + + Reset the statistics of "ioband1." + + # dmsetup message ioband1 0 reset + + + -------------------------------------------------------------------------- + +Examples + + Example #1: Bandwidth control on Partitions + + This example describes how to control the bandwidth with disk + partitions. The following diagram illustrates the configuration of this + example. You may want to run a database on /dev/mapper/ioband1 and web + applications on /dev/mapper/ioband2. + + /mnt1 /mnt2 mount points + | | + +-------------V------------+ +-------------V------------+ + | /dev/mapper/ioband1 | | /dev/mapper/ioband2 | ioband devices + +--------------------------+ +--------------------------+ + | default group | | default group | ioband groups + | (80) | | (40) | (weight) + +-------------|------------+ +-------------|------------+ + | | + +-------------V-------------+--------------V------------+ + | /dev/sda1 | /dev/sda2 | partitions + +---------------------------+---------------------------+ + + + To setup the above configuration, follow these steps: + + 1. Create ioband devices with the same device group ID and assign + weights of 80 and 40 to the default ioband groups respectively. + + # echo "0 $(blockdev --getsize /dev/sda1) ioband /dev/sda1 1 0 0" \ + "none weight 0 :80" | dmsetup create ioband1 + # echo "0 $(blockdev --getsize /dev/sda2) ioband /dev/sda2 1 0 0" \ + "none weight 0 :40" | dmsetup create ioband2 + + + 2. Create filesystems on the ioband devices and mount them. + + # mkfs.ext3 /dev/mapper/ioband1 + # mount /dev/mapper/ioband1 /mnt1 + + # mkfs.ext3 /dev/mapper/ioband2 + # mount /dev/mapper/ioband2 /mnt2 + + + -------------------------------------------------------------------------- + + Example #2: Bandwidth control on Logical Volumes + + This example is similar to the example #1 but it uses LVM logical + volumes instead of disk partitions. This example shows how to configure + ioband devices on two striped logical volumes. + + /mnt1 /mnt2 mount points + | | + +-------------V------------+ +-------------V------------+ + | /dev/mapper/ioband1 | | /dev/mapper/ioband2 | ioband devices + +--------------------------+ +--------------------------+ + | default group | | default group | ioband groups + | (80) | | (40) | (weight) + +-------------|------------+ +-------------|------------+ + | | + +-------------V------------+ +-------------V------------+ + | /dev/mapper/lv0 | | /dev/mapper/lv1 | striped logical + | | | | volumes + +-------------------------------------------------------+ + | vg0 | volume group + +-------------|----------------------------|------------+ + | | + +-------------V------------+ +-------------V------------+ + | /dev/sdb | | /dev/sdc | physical disks + +--------------------------+ +--------------------------+ + + + To setup the above configuration, follow these steps: + + 1. Initialize the partitions for use by LVM. + + # pvcreate /dev/sdb + # pvcreate /dev/sdc + + + 2. Create a new volume group named "vg0" with /dev/sdb and /dev/sdc. + + # vgcreate vg0 /dev/sdb /dev/sdc + + + 3. Create two logical volumes in "vg0." The volumes have to be striped. + + # lvcreate -n lv0 -i 2 -I 64 vg0 -L 1024M + # lvcreate -n lv1 -i 2 -I 64 vg0 -L 1024M + + + The rest is the same as the example #1. + + 4. Create ioband devices corresponding to each logical volume and + assign weights of 80 and 40 to the default ioband groups respectively. + + # echo "0 $(blockdev --getsize /dev/mapper/vg0-lv0)" \ + "ioband /dev/mapper/vg0-lv0 1 0 0 none weight 0 :80" | \ + dmsetup create ioband1 + # echo "0 $(blockdev --getsize /dev/mapper/vg0-lv1)" \ + "ioband /dev/mapper/vg0-lv1 1 0 0 none weight 0 :40" | \ + dmsetup create ioband2 + + + 5. Create filesystems on the ioband devices and mount them. + + # mkfs.ext3 /dev/mapper/ioband1 + # mount /dev/mapper/ioband1 /mnt1 + + # mkfs.ext3 /dev/mapper/ioband2 + # mount /dev/mapper/ioband2 /mnt2 + + + -------------------------------------------------------------------------- + + Example #4: Bandwidth control on processes + + This example describes how to control the bandwidth with groups of + processes. You may also want to run an additional application on the same + machine described in the example #1. This example shows how to add a new + ioband group for this application. + + /mnt1 /mnt2 mount points + | | + +-------------V------------+ +-------------V------------+ + | /dev/mapper/ioband1 | | /dev/mapper/ioband2 | ioband devices + +-------------+------------+ +-------------+------------+ + | default | | user=1000 | default | ioband groups + | (80) | | (20) | (40) | (weight) + +-------------+------------+ +-------------+------------+ + | | + +-------------V-------------+--------------V------------+ + | /dev/sda1 | /dev/sda2 | partitions + +---------------------------+---------------------------+ + + + The following shows to set up a new ioband group on the machine that is + already configured as the example #1. The application will have a weight + of 20 and run with user-id 1000 on /dev/mapper/ioband2. + + 1. Set the type of ioband2 to "user." + + # dmsetup message ioband2 0 type user. + + + 2. Create a new ioband group on ioband2. + + # dmsetup message ioband2 0 attach 1000 + + + 3. Assign weight of 10 to this newly created ioband group. + + # dmsetup message ioband2 0 weight 1000:20 + + + -------------------------------------------------------------------------- + + Example #3: Bandwidth control for Xen virtual block devices + + This example describes how to control the bandwidth for Xen virtual + block devices. The following diagram illustrates the configuration of this + example. + + Virtual Machine 1 Virtual Machine 2 virtual machines + | | + +-------------V------------+ +-------------V------------+ + | /dev/xvda1 | | /dev/xvda1 | virtual block + +-------------|------------+ +-------------|------------+ devices + | | + +-------------V------------+ +-------------V------------+ + | /dev/mapper/ioband1 | | /dev/mapper/ioband2 | ioband devices + +--------------------------+ +--------------------------+ + | default group | | default group | ioband groups + | (80) | | (40) | (weight) + +-------------|------------+ +-------------|------------+ + | | + +-------------V-------------+--------------V------------+ + | /dev/sda1 | /dev/sda2 | partitions + +---------------------------+---------------------------+ + + + The followings shows how to map ioband device "ioband1" and "ioband2" to + virtual block device "/dev/xvda1 on Virtual Machine 1" and "/dev/xvda1 on + Virtual Machine 2" respectively on the machine configured as the example + #1. Add the following lines to the configuration files that are referenced + when creating "Virtual Machine 1" and "Virtual Machine 2." + + For "Virtual Machine 1" + disk = [ 'phy:/dev/mapper/ioband1,xvda,w' ] + + For "Virtual Machine 2" + disk = [ 'phy:/dev/mapper/ioband2,xvda,w' ] + + + -------------------------------------------------------------------------- + + Example #4: Bandwidth control for Xen blktap devices + + This example describes how to control the bandwidth for Xen virtual + block devices when Xen blktap devices are used. The following diagram + illustrates the configuration of this example. + + Virtual Machine 1 Virtual Machine 2 virtual machines + | | + +-------------V------------+ +-------------V------------+ + | /dev/xvda1 | | /dev/xvda1 | virtual block + +-------------|------------+ +-------------|------------+ devices + | | + +----------V----------+ +-----------V---------+ + | tapdisk | | tapdisk | tapdisk daemons + | (15011) | | (15276) | (daemon's pid) + +----------|----------+ +-----------|---------+ + | | + +-------------|----------------------------|------------+ + | | /dev/mapper/ioband1 | | ioband device + | | mount on /vmdisk | | + +-------------V-------------+--------------V------------+ + | group for PID=15011 | group for PID=15276 | ioband groups + | (80) | (40) | (weight) + +-------------|----------------------------|------------+ + | | + +-------------|----------------------------|------------+ + | +----------V----------+ +-----------V---------+ | + | | vm1.img | | vm2.img | | disk image files + | +---------------------+ +---------------------+ | + | /dev/sda1 | partition + +-------------------------------------------------------+ + + + To setup the above configuration, follow these steps: + + 1. Create an ioband device. + + # echo "0 $(blockdev --getsize /dev/sda1) ioband /dev/sda1" \ + "1 0 0 none weight 0 :100" | dmsetup create ioband1 + + + 2. Add the following lines to the configuration files that are + referenced when creating "Virtual Machine 1" and "Virtual Machine 2." + Disk image files "/vmdisk/vm1.img" and "/vmdisk/vm2.img" will be used. + + For "Virtual Machine 1" + disk = [ 'tap:aio:/vmdisk/vm1.img,xvda,w', ] + + For "Virtual Machine 1" + disk = [ 'tap:aio:/vmdisk/vm2.img,xvda,w', ] + + + 3. Run the virtual machines. + + # xm create vm1 + # xm create vm2 + + + 4. Find out the process IDs of the daemons which control the blktap + devices. + + # lsof /vmdisk/disk[12].img + COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME + tapdisk 15011 root 11u REG 253,0 2147483648 48961 /vmdisk/vm1.img + tapdisk 15276 root 13u REG 253,0 2147483648 48962 /vmdisk/vm2.img + + + 5. Create new ioband groups of pid 15011 and pid 15276, which are + process IDs of the tapdisks, and assign weight of 80 and 40 to the + groups respectively. + + # dmsetup message ioband1 0 type pid + # dmsetup message ioband1 0 attach 15011 + # dmsetup message ioband1 0 weight 15011:80 + # dmsetup message ioband1 0 attach 15276 + # dmsetup message ioband1 0 weight 15276:40 Index: linux-2.6.31/drivers/md/Kconfig =================================================================== --- linux-2.6.31.orig/drivers/md/Kconfig +++ linux-2.6.31/drivers/md/Kconfig @@ -294,4 +294,17 @@ config DM_UEVENT ---help--- Generate udev events for DM events.

+config DM_IOBAND + tristate "I/O bandwidth control (EXPERIMENTAL)" + depends on BLK_DEV_DM && EXPERIMENTAL + ---help--- + This device-mapper target allows to define how the + available bandwidth of a storage device should be + shared between processes, cgroups, the partitions or the LUNs. + + Information on how to use dm-ioband is available in: + <file:Documentation/device-mapper/ioband.txt>. + + If unsure, say N. + endif # MD Index: linux-2.6.31/drivers/md/Makefile =================================================================== --- linux-2.6.31.orig/drivers/md/Makefile +++ linux-2.6.31/drivers/md/Makefile @@ -8,6 +8,8 @@ dm-multipath-y += dm-path-selector.o dm- dm-snapshot-y += dm-snap.o dm-exception-store.o dm-snap-transient.o \ dm-snap-persistent.o dm-mirror-y += dm-raid1.o +dm-ioband-y += dm-ioband-ctl.o dm-ioband-policy.o dm-ioband-rangebw.o \ + dm-ioband-type.o dm-log-userspace-y \ += dm-log-userspace-base.o dm-log-userspace-transfer.o md-mod-y += md.o bitmap.o @@ -37,6 +39,7 @@ obj-$(CONFIG_BLK_DEV_MD) += md-mod.o obj-$(CONFIG_BLK_DEV_DM) += dm-mod.o obj-$(CONFIG_DM_CRYPT) += dm-crypt.o obj-$(CONFIG_DM_DELAY) += dm-delay.o +obj-$(CONFIG_DM_IOBAND) += dm-ioband.o obj-$(CONFIG_DM_MULTIPATH) += dm-multipath.o dm-round-robin.o obj-$(CONFIG_DM_MULTIPATH_QL) += dm-queue-length.o obj-$(CONFIG_DM_MULTIPATH_ST) += dm-service-time.o Index: linux-2.6.31/drivers/md/dm-ioband-ctl.c =================================================================== --- /dev/null +++ linux-2.6.31/drivers/md/dm-ioband-ctl.c @@ -0,0 +1,1357 @@ +/* + * Copyright (C) 2008-2009 VA Linux Systems Japan K.K. + * Authors: Hirokazu Takahashi <ta@valinux.co.jp> + * Ryo Tsuruta <ry@valinux.co.jp> + * + * I/O bandwidth control + * + * Some blktrace messages were added by Alan D. Brunelle <Alan@hp.com> + * + * This file is released under the GPL. + */ +#include <linux/module.h> +#include <linux/init.h> +#include <linux/bio.h> +#include <linux/slab.h> +#include <linux/workqueue.h> +#include <linux/rbtree.h> +#include "dm.h" +#include "md.h" +#include "dm-ioband.h" + +#define CREATE_TRACE_POINTS +#include <trace/events/dm-ioband.h> + +static LIST_HEAD(ioband_device_list); +/* lock up during configuration */ +static DEFINE_MUTEX(ioband_lock); + +static void suspend_ioband_device(struct ioband_device *, unsigned long, int); +static void resume_ioband_device(struct ioband_device *); +static void ioband_conduct(struct work_struct *); +static void ioband_hold_bio(struct ioband_group *, struct bio *); +static struct bio *ioband_pop_bio(struct ioband_group *); +static int ioband_set_param(struct ioband_group *, const char *, const char *); +static int ioband_group_attach(struct ioband_group *, int, int, const char *); +static int ioband_group_type_select(struct ioband_group *, const char *); + +static void do_nothing(void) {} + +static int policy_init(struct ioband_device *dp, const char *name, + int argc, char **argv) +{ + const struct ioband_policy_type *p; + struct ioband_group *gp; + unsigned long flags; + int r; + + for (p = dm_ioband_policy_type; p->p_name; p++) { + if (!strcmp(name, p->p_name)) + break; + } + if (!p->p_name) + return -EINVAL; + /* do nothing if the same policy is already set */ + if (dp->g_policy == p) + return 0; + + spin_lock_irqsave(&dp->g_lock, flags); + suspend_ioband_device(dp, flags, 1); + list_for_each_entry(gp, &dp->g_groups, c_list) + dp->g_group_dtr(gp); + + /* switch to the new policy */ + dp->g_policy = p; + r = p->p_policy_init(dp, argc, argv); + if (!r) { + if (!dp->g_hold_bio) + dp->g_hold_bio = ioband_hold_bio; + if (!dp->g_pop_bio) + dp->g_pop_bio = ioband_pop_bio; + + list_for_each_entry(gp, &dp->g_groups, c_list) + dp->g_group_ctr(gp, NULL); + } + resume_ioband_device(dp); + spin_unlock_irqrestore(&dp->g_lock, flags); + return r; +} + +static struct ioband_device *alloc_ioband_device(const char *name, + int io_throttle, int io_limit) +{ + struct ioband_device *dp, *new_dp; + + new_dp = kzalloc(sizeof(struct ioband_device), GFP_KERNEL); + if (!new_dp) + return NULL; + + /* + * Prepare its own workqueue as generic_make_request() may + * potentially block the workqueue when submitting BIOs. + */ + new_dp->g_ioband_wq = create_workqueue("kioband"); + if (!new_dp->g_ioband_wq) { + kfree(new_dp); + return NULL; + } + + list_for_each_entry(dp, &ioband_device_list, g_list) { + if (!strcmp(dp->g_name, name)) { + dp->g_ref++; + destroy_workqueue(new_dp->g_ioband_wq); + kfree(new_dp); + return dp; + } + } + + INIT_DELAYED_WORK(&new_dp->g_conductor, ioband_conduct); + INIT_LIST_HEAD(&new_dp->g_groups); + INIT_LIST_HEAD(&new_dp->g_list); + INIT_LIST_HEAD(&new_dp->g_root_groups); + spin_lock_init(&new_dp->g_lock); + bio_list_init(&new_dp->g_urgent_bios); + new_dp->g_io_throttle = io_throttle; + new_dp->g_io_limit = io_limit; + new_dp->g_issued[BLK_RW_SYNC] = 0; + new_dp->g_issued[BLK_RW_ASYNC] = 0; + new_dp->g_blocked = 0; + new_dp->g_ref = 1; + new_dp->g_flags = 0; + strlcpy(new_dp->g_name, name, sizeof(new_dp->g_name)); + new_dp->g_policy = NULL; + new_dp->g_hold_bio = NULL; + new_dp->g_pop_bio = NULL; + init_waitqueue_head(&new_dp->g_waitq); + init_waitqueue_head(&new_dp->g_waitq_suspend); + init_waitqueue_head(&new_dp->g_waitq_flush); + list_add_tail(&new_dp->g_list, &ioband_device_list); + return new_dp; +} + +static void release_ioband_device(struct ioband_device *dp) +{ + dp->g_ref--; + if (dp->g_ref > 0) + return; + list_del(&dp->g_list); + destroy_workqueue(dp->g_ioband_wq); + kfree(dp); +} + +static int is_ioband_device_flushed(struct ioband_device *dp, + int wait_completion) +{ + struct ioband_group *gp; + + if (wait_completion && nr_issued(dp) > 0) + return 0; + if (dp->g_blocked || waitqueue_active(&dp->g_waitq)) + return 0; + list_for_each_entry(gp, &dp->g_groups, c_list) + if (waitqueue_active(&gp->c_waitq)) + return 0; + return 1; +} + +static void suspend_ioband_device(struct ioband_device *dp, + unsigned long flags, int wait_completion) +{ + struct ioband_group *gp; + + /* block incoming bios */ + set_device_suspended(dp); + + /* wake up all blocked processes and go down all ioband groups */ + wake_up_all(&dp->g_waitq); + list_for_each_entry(gp, &dp->g_groups, c_list) { + if (!is_group_down(gp)) { + set_group_down(gp); + set_group_need_up(gp); + } + wake_up_all(&gp->c_waitq); + } + + /* flush the already mapped bios */ + spin_unlock_irqrestore(&dp->g_lock, flags); + queue_delayed_work(dp->g_ioband_wq, &dp->g_conductor, 0); + flush_workqueue(dp->g_ioband_wq); + + /* wait for all processes to wake up and bios to release */ + spin_lock_irqsave(&dp->g_lock, flags); + wait_event_lock_irq(dp->g_waitq_flush, + is_ioband_device_flushed(dp, wait_completion), + dp->g_lock, do_nothing()); +} + +static void resume_ioband_device(struct ioband_device *dp) +{ + struct ioband_group *gp; + + /* go up ioband groups */ + list_for_each_entry(gp, &dp->g_groups, c_list) { + if (group_need_up(gp)) { + clear_group_need_up(gp); + clear_group_down(gp); + } + } + + /* accept incoming bios */ + wake_up_all(&dp->g_waitq_suspend); + clear_device_suspended(dp); +} + +static struct ioband_group *ioband_group_find(struct ioband_group *head, int
id) +{ + struct rb_node *node = head->c_group_root.rb_node; + + while (node) { + struct ioband_group *p = + rb_entry(node, struct ioband_group, c_group_node); + + if (p->c_id == id || id == IOBAND_ID_ANY) + return p; + node = (id < p->c_id) ? node->rb_left : node->rb_right; + } + return NULL; +} + +static void ioband_group_add_node(struct rb_root *root, struct ioband_group
*gp) +{ + struct rb_node **node = &root->rb_node, *parent = NULL; + struct ioband_group *p; + + while (*node) { + p = rb_entry(*node, struct ioband_group, c_group_node); + parent = *node; + node = (gp->c_id < p->c_id) ? + &(*node)->rb_left : &(*node)->rb_right; + } + + rb_link_node(&gp->c_group_node, parent, node); + rb_insert_color(&gp->c_group_node, root); +} + +static int ioband_group_init(struct ioband_device *dp, + struct ioband_group *head, + struct ioband_group *parent, + struct ioband_group *gp, + int id, const char *param) +{ + unsigned long flags; + int r; + + INIT_LIST_HEAD(&gp->c_list); + INIT_LIST_HEAD(&gp->c_sibling); + INIT_LIST_HEAD(&gp->c_children); + gp->c_parent = parent; + bio_list_init(&gp->c_blocked_bios); + bio_list_init(&gp->c_prio_bios); + gp->c_id = id; /* should be verified */ + gp->c_blocked = 0; + gp->c_prio_blocked = 0; + memset(&gp->c_stats, 0, sizeof(gp->c_stats)); + init_waitqueue_head(&gp->c_waitq); + gp->c_flags = 0; + gp->c_group_root = RB_ROOT; + gp->c_banddev = dp; + + spin_lock_irqsave(&dp->g_lock, flags); + if (head && ioband_group_find(head, id)) { + spin_unlock_irqrestore(&dp->g_lock, flags); + DMWARN("%s: id=%d already exists.", __func__, id); + return -EEXIST; + } + + list_add_tail(&gp->c_list, &dp->g_groups); + + if (!parent) + list_add_tail(&gp->c_sibling, &dp->g_root_groups); + else + list_add_tail(&gp->c_sibling, &parent->c_children); + + r = dp->g_group_ctr(gp, param); + if (r) { + list_del(&gp->c_list); + list_del(&gp->c_sibling); + spin_unlock_irqrestore(&dp->g_lock, flags); + return r; + } + + if (head) { + ioband_group_add_node(&head->c_group_root, gp); + gp->c_dev = head->c_dev; + gp->c_target = head->c_target; + } + + spin_unlock_irqrestore(&dp->g_lock, flags); + return 0; +} + +static void ioband_group_release(struct ioband_group *head, + struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + + list_del(&gp->c_list); + list_del(&gp->c_sibling); + if (head) + rb_erase(&gp->c_group_node, &head->c_group_root); + dp->g_group_dtr(gp); + kfree(gp); +} + +static void ioband_group_destroy_all(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + struct ioband_group *p; + unsigned long flags; + + spin_lock_irqsave(&dp->g_lock, flags); + while ((p = ioband_group_find(gp, IOBAND_ID_ANY))) + ioband_group_release(gp, p); + ioband_group_release(NULL, gp); + spin_unlock_irqrestore(&dp->g_lock, flags); +} + +static void ioband_group_stop_all(struct ioband_group *head, int suspend) +{ + struct ioband_device *dp = head->c_banddev; + struct ioband_group *p; + struct rb_node *node; + unsigned long flags; + + spin_lock_irqsave(&dp->g_lock, flags); + for (node = rb_first(&head->c_group_root); node; node = rb_next(node)) { + p = rb_entry(node, struct ioband_group, c_group_node); + set_group_down(p); + if (suspend) + set_group_suspended(p); + } + set_group_down(head); + if (suspend) + set_group_suspended(head); + spin_unlock_irqrestore(&dp->g_lock, flags); + queue_delayed_work(dp->g_ioband_wq, &dp->g_conductor, 0); + flush_workqueue(dp->g_ioband_wq); +} + +static void ioband_group_resume_all(struct ioband_group *head) +{ + struct ioband_device *dp = head->c_banddev; + struct ioband_group *p; + struct rb_node *node; + unsigned long flags; + + spin_lock_irqsave(&dp->g_lock, flags); + for (node = rb_first(&head->c_group_root); node; node = rb_next(node)) { + p = rb_entry(node, struct ioband_group, c_group_node); + clear_group_down(p); + clear_group_suspended(p); + } + clear_group_down(head); + clear_group_suspended(head); + spin_unlock_irqrestore(&dp->g_lock, flags); +} + +static int parse_group_param(const char *param, long *id, char const **value) +{ + char *s, *endp; + long n; + + s = strpbrk(param, POLICY_PARAM_DELIM); + if (!s) { + *id = IOBAND_ID_ANY; + *value = param; + return 0; + } + + n = simple_strtol(param, &endp, 0); + if (endp != s) + return -EINVAL; + + *id = (endp == param) ? IOBAND_ID_ANY : n; + *value = endp + 1; + return 0; +} + +/* + * Create a new band device: + * parameters: <device> <device-group-id> <io_throttle> <io_limit> + * <type> <policy> <policy-param...> <group-id:group-param...> + */ +static int ioband_ctr(struct dm_target *ti, unsigned argc, char **argv) +{ + struct ioband_group *gp; + struct ioband_device *dp; + struct dm_dev *dev; + int io_throttle; + int io_limit; + int i, r, start; + long val, id; + const char *param; + char *s; + + if (argc < POLICY_PARAM_START) { + ti->error = "Requires " __stringify(POLICY_PARAM_START) + " or more arguments"; + return -EINVAL; + } + + if (strlen(argv[1]) > IOBAND_NAME_MAX) { + ti->error = "Ioband device name is too long"; + return -EINVAL; + } + + r = strict_strtol(argv[2], 0, &val); + if (r || val < 0 || val > SHORT_MAX) { + ti->error = "Invalid io_throttle"; + return -EINVAL; + } + io_throttle = (val == 0) ? DEFAULT_IO_THROTTLE : val; + + r = strict_strtol(argv[3], 0, &val); + if (r || val < 0 || val > SHORT_MAX) { + ti->error = "Invalid io_limit"; + return -EINVAL; + } + io_limit = val; + + r = dm_get_device(ti, argv[0], 0, ti->len, + dm_table_get_mode(ti->table), &dev); + if (r) { + ti->error = "Device lookup failed"; + return r; + } + + if (io_limit == 0) { + struct request_queue *q; + + q = bdev_get_queue(dev->bdev); + if (!q) { + ti->error = "Can't get queue size"; + r = -ENXIO; + goto release_dm_device; + } + /* + * The block layer accepts I/O requests up to 50% over + * nr_requests when the requests are issued from a + * "batcher" process. + */ + io_limit = (3 * q->nr_requests / 2); + } + + if (io_limit < io_throttle) + io_limit = io_throttle; + + mutex_lock(&ioband_lock); + dp = alloc_ioband_device(argv[1], io_throttle, io_limit); + if (!dp) { + ti->error = "Cannot create ioband device"; + r = -EINVAL; + mutex_unlock(&ioband_lock); + goto release_dm_device; + } + + r = policy_init(dp, argv[POLICY_PARAM_START - 1], + argc - POLICY_PARAM_START, &argv[POLICY_PARAM_START]); + if (r) { + ti->error = "Invalid policy parameter"; + goto release_ioband_device; + } + + gp = kzalloc(sizeof(struct ioband_group), GFP_KERNEL); + if (!gp) { + ti->error = "Cannot allocate memory for ioband group"; + r = -ENOMEM; + goto release_ioband_device; + } + + ti->num_flush_requests = 1; + ti->private = gp; + gp->c_target = ti; + gp->c_dev = dev; + + /* Find a default group parameter */ + for (start = POLICY_PARAM_START; start < argc; start++) { + s = strpbrk(argv[start], POLICY_PARAM_DELIM); + if (s == argv[start]) + break; + } + param = (start < argc) ? &argv[start][1] : NULL; + + /* Create a default ioband group */ + r = ioband_group_init(dp, NULL, NULL, gp, IOBAND_ID_ANY, param); + if (r) { + kfree(gp); + ti->error = "Cannot create default ioband group"; + goto release_ioband_device; + } + + r = ioband_group_type_select(gp, argv[4]); + if (r) { + ti->error = "Cannot set ioband group type"; + goto release_ioband_group; + } + + /* Create sub ioband groups */ + for (i = start + 1; i < argc; i++) { + r = parse_group_param(argv[i], &id, &param); + if (r) { + ti->error = "Invalid ioband group parameter"; + goto release_ioband_group; + } + r = ioband_group_attach(gp, 0, id, param); + if (r) { + ti->error = "Cannot create ioband group"; + goto release_ioband_group; + } + } + mutex_unlock(&ioband_lock); + return 0; + +release_ioband_group: + ioband_group_destroy_all(gp); +release_ioband_device: + release_ioband_device(dp); + mutex_unlock(&ioband_lock); +release_dm_device: + dm_put_device(ti, dev); + return r; +} + +static void ioband_dtr(struct dm_target *ti) +{ + struct ioband_group *gp = ti->private; + struct ioband_device *dp = gp->c_banddev; + struct dm_dev *dev = gp->c_dev; + + mutex_lock(&ioband_lock); + + ioband_group_stop_all(gp, 0); + cancel_delayed_work_sync(&dp->g_conductor); + ioband_group_destroy_all(gp); + + release_ioband_device(dp); + mutex_unlock(&ioband_lock); + + dm_put_device(ti, dev); +} + +static void ioband_hold_bio(struct ioband_group *gp, struct bio *bio) +{ + /* Todo: The list should be split into a sync list and an async list */ + bio_list_add(&gp->c_blocked_bios, bio); +} + +static struct bio *ioband_pop_bio(struct ioband_group *gp) +{ + return bio_list_pop(&gp->c_blocked_bios); +} + +static int is_urgent_bio(struct bio *bio) +{ + struct page *page = bio_iovec_idx(bio, 0)->bv_page; + /* + * ToDo: A new flag should be added to struct bio, which indicates + * it contains urgent I/O requests. + */ + if (!PageReclaim(page)) + return 0; + if (PageSwapCache(page)) + return 2; + return 1; +} + +static inline int device_should_block(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + + if (is_group_down(gp)) + return 0; + if (is_device_blocked(dp)) + return 1; + if (dp->g_blocked >= dp->g_io_limit * 2) { + set_device_blocked(dp); + return 1; + } + return 0; +} + +static inline int group_should_block(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + + if (is_group_down(gp)) + return 0; + if (is_group_blocked(gp)) + return 1; + if (dp->g_should_block(gp)) { + set_group_blocked(gp); + return 1; + } + return 0; +} + +static void prevent_burst_bios(struct ioband_group *gp, struct bio *bio) +{ + struct ioband_device *dp = gp->c_banddev; + + if (current->flags & PF_KTHREAD || is_urgent_bio(bio)) { + /* + * Kernel threads shouldn't be blocked easily since each of + * them may handle BIOs for several groups on several + * partitions. + */ + wait_event_lock_irq(dp->g_waitq, !device_should_block(gp), + dp->g_lock, do_nothing()); + } else { + wait_event_lock_irq(gp->c_waitq, !group_should_block(gp), + dp->g_lock, do_nothing()); + } +} + +static inline int should_pushback_bio(struct ioband_group *gp) +{ + return is_group_suspended(gp) && dm_noflush_suspending(gp->c_target); +} + +static inline bool bio_is_sync(struct bio *bio) +{ + /* Must be the same condition as rw_is_sync() in blkdev.h */ + return !bio_data_dir(bio) || bio_sync(bio); +} + +static inline int prepare_to_issue(struct ioband_group *gp, struct bio *bio) +{ + struct ioband_device *dp = gp->c_banddev; + + dp->g_issued[bio_is_sync(bio)]++; + return dp->g_prepare_bio(gp, bio, 0); +} + +static inline int room_for_bio(struct ioband_device *dp) +{ + return dp->g_issued[BLK_RW_SYNC] < dp->g_io_limit + || dp->g_issued[BLK_RW_ASYNC] < dp->g_io_limit; +} + +static void hold_bio(struct ioband_group *gp, struct bio *bio) +{ + struct ioband_device *dp = gp->c_banddev; + + dp->g_blocked++; + if (is_urgent_bio(bio)) { + dp->g_prepare_bio(gp, bio, IOBAND_URGENT); + bio_list_add(&dp->g_urgent_bios, bio); + trace_ioband_hold_urgent_bio(gp, bio); + } else { + gp->c_blocked++; + dp->g_hold_bio(gp, bio); + trace_ioband_hold_bio(gp, bio); + } +} + +static inline int room_for_bio_sync(struct ioband_device *dp, int sync) +{ + return dp->g_issued[sync] < dp->g_io_limit; +} + +static void push_prio_bio(struct ioband_group *gp, struct bio *bio, int sync) +{ + if (bio_list_empty(&gp->c_prio_bios)) + set_prio_queue(gp, sync); + bio_list_add(&gp->c_prio_bios, bio); + gp->c_prio_blocked++; +} + +static struct bio *pop_prio_bio(struct ioband_group *gp) +{ + struct bio *bio = bio_list_pop(&gp->c_prio_bios); + + if (bio_list_empty(&gp->c_prio_bios)) + clear_prio_queue(gp); + + if (bio) + gp->c_prio_blocked--; + return bio; +} + +static int make_issue_list(struct ioband_group *gp, struct bio *bio, + struct bio_list *issue_list, + struct bio_list *pushback_list) +{ + struct ioband_device *dp = gp->c_banddev; + + dp->g_blocked--; + gp->c_blocked--; + if (!gp->c_blocked && is_group_blocked(gp)) { + clear_group_blocked(gp); + wake_up_all(&gp->c_waitq); + } + if (should_pushback_bio(gp)) { + bio_list_add(pushback_list, bio); + trace_ioband_make_pback_list(gp, bio); + } else { + int rw = bio_data_dir(bio); + + gp->c_stats.sectors[rw] += bio_sectors(bio); + gp->c_stats.ios[rw]++; + bio_list_add(issue_list, bio); + trace_ioband_make_issue_list(gp, bio); + } + return prepare_to_issue(gp, bio); +} + +static void release_urgent_bios(struct ioband_device *dp, + struct bio_list *issue_list, + struct bio_list *pushback_list) +{ + struct bio *bio; + + if (bio_list_empty(&dp->g_urgent_bios)) + return; + while (room_for_bio_sync(dp, BLK_RW_ASYNC)) { + bio = bio_list_pop(&dp->g_urgent_bios); + if (!bio) + return; + dp->g_blocked--; + dp->g_issued[bio_is_sync(bio)]++; + bio_list_add(issue_list, bio); + trace_ioband_release_urgent_bios(dp, bio); + } +} + +static int release_prio_bios(struct ioband_group *gp, + struct bio_list *issue_list, + struct bio_list *pushback_list) +{ + struct ioband_device *dp = gp->c_banddev; + struct bio *bio; + int sync; + int ret; + + if (bio_list_empty(&gp->c_prio_bios)) + return R_OK; + sync = prio_queue_sync(gp); + while (gp->c_prio_blocked) { + if (!dp->g_can_submit(gp)) + return R_BLOCK; + if (!room_for_bio_sync(dp, sync)) + return R_OK; + bio = pop_prio_bio(gp); + if (!bio) + return R_OK; + ret = make_issue_list(gp, bio, issue_list, pushback_list); + if (ret) + return ret; + } + return R_OK; +} + +static int release_norm_bios(struct ioband_group *gp, + struct bio_list *issue_list, + struct bio_list *pushback_list) +{ + struct ioband_device *dp = gp->c_banddev; + struct bio *bio; + int sync, ret; + + while (gp->c_blocked - gp->c_prio_blocked) { + if (!dp->g_can_submit(gp)) + return R_BLOCK; + if (!room_for_bio(dp)) + return R_OK; + bio = dp->g_pop_bio(gp); + if (!bio) + return R_OK; + + sync = bio_is_sync(bio); + if (!room_for_bio_sync(dp, sync)) { + push_prio_bio(gp, bio, sync); + continue; + } + ret = make_issue_list(gp, bio, issue_list, pushback_list); + if (ret) + return ret; + } + return R_OK; +} + +static inline int release_bios(struct ioband_group *gp, + struct bio_list *issue_list, + struct bio_list *pushback_list) +{ + int ret = release_prio_bios(gp, issue_list, pushback_list); + if (ret) + return ret; + return release_norm_bios(gp, issue_list, pushback_list); +} + +static struct ioband_group *ioband_group_get(struct ioband_group *head, + struct bio *bio) +{ + struct ioband_group *gp; + + if (!head->c_type->t_getid) + return head; + + gp = ioband_group_find(head, head->c_type->t_getid(bio)); + + if (!gp) + gp = head; + return gp; +} + +/* + * Start to control the bandwidth once the number of uncompleted BIOs + * exceeds the value of "io_throttle". + */ +static int ioband_map(struct dm_target *ti, struct bio *bio, + union map_info *map_context) +{ + struct ioband_group *gp = ti->private; + struct ioband_device *dp = gp->c_banddev; + unsigned long flags; + int rw; + + spin_lock_irqsave(&dp->g_lock, flags); + + /* + * The device is suspended while some of the ioband device + * configurations are being changed. + */ + if (is_device_suspended(dp)) + wait_event_lock_irq(dp->g_waitq_suspend, + !is_device_suspended(dp), dp->g_lock, + do_nothing()); + + gp = ioband_group_get(gp, bio); + prevent_burst_bios(gp, bio); + if (should_pushback_bio(gp)) { + spin_unlock_irqrestore(&dp->g_lock, flags); + return DM_MAPIO_REQUEUE; + } + + bio->bi_bdev = gp->c_dev->bdev; + if (bio_sectors(bio)) + bio->bi_sector -= ti->begin; + + if (!gp->c_blocked && room_for_bio_sync(dp, bio_is_sync(bio))) { + if (dp->g_can_submit(gp)) { + prepare_to_issue(gp, bio); + rw = bio_data_dir(bio); + gp->c_stats.sectors[rw] += bio_sectors(bio); + gp->c_stats.ios[rw]++; + spin_unlock_irqrestore(&dp->g_lock, flags); + return DM_MAPIO_REMAPPED; + } else if (!dp->g_blocked && nr_issued(dp) == 0) { + DMDEBUG("%s: token expired gp:%p", __func__, gp); + queue_delayed_work(dp->g_ioband_wq, + &dp->g_conductor, 1); + } + } + hold_bio(gp, bio); + spin_unlock_irqrestore(&dp->g_lock, flags); + + return DM_MAPIO_SUBMITTED; +} + +/* + * Select the best group to resubmit its BIOs. + */ +static struct ioband_group *choose_best_group(struct ioband_device *dp) +{ + struct ioband_group *gp; + struct ioband_group *best = NULL; + int highest = 0; + int pri; + + /* Todo: The algorithm should be optimized. + * It would be better to use rbtree. + */ + list_for_each_entry(gp, &dp->g_groups, c_list) { + if (!gp->c_blocked || !room_for_bio(dp)) + continue; + if (gp->c_blocked == gp->c_prio_blocked && + !room_for_bio_sync(dp, prio_queue_sync(gp))) { + continue; + } + pri = dp->g_can_submit(gp); + if (pri > highest) { + highest = pri; + best = gp; + } + } + + return best; +} + +/* + * This function is called right after it becomes able to resubmit BIOs. + * It selects the best BIOs and passes them to the underlying layer. + */ +static void ioband_conduct(struct work_struct *work) +{ + struct ioband_device *dp = + container_of(work, struct ioband_device, g_conductor.work); + struct ioband_group *gp = NULL; + struct bio *bio; + unsigned long flags; + struct bio_list issue_list, pushback_list; + + bio_list_init(&issue_list); + bio_list_init(&pushback_list); + + spin_lock_irqsave(&dp->g_lock, flags); + release_urgent_bios(dp, &issue_list, &pushback_list); + if (dp->g_blocked) { + gp = choose_best_group(dp); + if (gp && + release_bios(gp, &issue_list, &pushback_list) == R_YIELD) + queue_delayed_work(dp->g_ioband_wq, + &dp->g_conductor, 0); + } + + if (is_device_blocked(dp) && dp->g_blocked < dp->g_io_limit * 2) { + clear_device_blocked(dp); + wake_up_all(&dp->g_waitq); + } + + if (dp->g_blocked && + room_for_bio_sync(dp, BLK_RW_SYNC) && + room_for_bio_sync(dp, BLK_RW_ASYNC) && + bio_list_empty(&issue_list) && bio_list_empty(&pushback_list) && + dp->g_restart_bios(dp)) { + DMDEBUG("%s: token expired dp:%p issued(%d,%d) g_blocked(%d)", + __func__, dp, + dp->g_issued[BLK_RW_SYNC], dp->g_issued[BLK_RW_ASYNC], + dp->g_blocked); + queue_delayed_work(dp->g_ioband_wq, &dp->g_conductor, 0); + } + + spin_unlock_irqrestore(&dp->g_lock, flags); + + while ((bio = bio_list_pop(&issue_list))) { + trace_ioband_make_request(dp, bio); + generic_make_request(bio); + } + + while ((bio = bio_list_pop(&pushback_list))) { + trace_ioband_pushback_bio(dp, bio); + bio_endio(bio, -EIO); + } +} + +static int ioband_end_io(struct dm_target *ti, struct bio *bio, + int error, union map_info *map_context) +{ + struct ioband_group *gp = ti->private; + struct ioband_device *dp = gp->c_banddev; + unsigned long flags; + int r = error; + + /* + * XXX: A new error code for device mapper devices should be used + * rather than EIO. + */ + if (error == -EIO && should_pushback_bio(gp)) { + /* This ioband device is suspending */ + r = DM_ENDIO_REQUEUE; + } + /* + * Todo: The algorithm should be optimized to eliminate the spinlock. + */ + spin_lock_irqsave(&dp->g_lock, flags); + dp->g_issued[bio_is_sync(bio)]--; + + /* + * Todo: It would be better to introduce high/low water marks here + * not to kick the workqueues so often. + */ + if (dp->g_blocked) + queue_delayed_work(dp->g_ioband_wq, &dp->g_conductor, 0); + else if (is_device_suspended(dp) && nr_issued(dp) == 0) + wake_up_all(&dp->g_waitq_flush); + spin_unlock_irqrestore(&dp->g_lock, flags); + return r; +} + +static void ioband_presuspend(struct dm_target *ti) +{ + struct ioband_group *gp = ti->private; + + ioband_group_stop_all(gp, 1); +} + +static void ioband_resume(struct dm_target *ti) +{ + struct ioband_group *gp = ti->private; + + ioband_group_resume_all(gp); +} + +static void ioband_group_status(struct ioband_group *gp, int *szp, + char *result, unsigned maxlen) +{ + int sz = *szp; /* used in DMEMIT() */ + struct disk_stats *st = &gp->c_stats; + + DMEMIT(" %d %lu %lu %lu %lu %lu %lu %lu %lu %d %lu %lu", + gp->c_id, + st->ios[0], st->merges[0], st->sectors[0], st->ticks[0], + st->ios[1], st->merges[1], st->sectors[1], st->ticks[1], + gp->c_blocked, st->io_ticks, st->time_in_queue); + *szp = sz; +} + +static int ioband_status(struct dm_target *ti, status_type_t type, + char *result, unsigned maxlen) +{ + struct ioband_group *gp = ti->private, *p; + struct ioband_device *dp = gp->c_banddev; + struct rb_node *node; + int sz = 0; /* used in DMEMIT() */ + unsigned long flags; + + spin_lock_irqsave(&dp->g_lock, flags); + + switch (type) { + case STATUSTYPE_INFO: + DMEMIT("%s", dp->g_name); + ioband_group_status(gp, &sz, result, maxlen); + for (node = rb_first(&gp->c_group_root); node; + node = rb_next(node)) { + p = rb_entry(node, struct ioband_group, c_group_node); + ioband_group_status(p, &sz, result, maxlen); + } + break; + + case STATUSTYPE_TABLE: + DMEMIT("%s %s %d %d %s %s", + gp->c_dev->name, dp->g_name, + dp->g_io_throttle, dp->g_io_limit, + gp->c_type->t_name, dp->g_policy->p_name); + dp->g_show(gp, &sz, result, maxlen); + break; + } + + spin_unlock_irqrestore(&dp->g_lock, flags); + return 0; +} + +static int ioband_group_type_select(struct ioband_group *gp, const char *name) +{ + struct ioband_device *dp = gp->c_banddev; + const struct ioband_group_type *t; + unsigned long flags; + + for (t = dm_ioband_group_type; (t->t_name); t++) { + if (!strcmp(name, t->t_name)) + break; + } + if (!t->t_name) { + DMWARN("%s: %s isn't supported.", __func__, name); + return -EINVAL; + } + spin_lock_irqsave(&dp->g_lock, flags); + if (!RB_EMPTY_ROOT(&gp->c_group_root)) { + spin_unlock_irqrestore(&dp->g_lock, flags); + return -EBUSY; + } + gp->c_type = t; + spin_unlock_irqrestore(&dp->g_lock, flags); + + return 0; +} + +static int ioband_set_param(struct ioband_group *gp, + const char *cmd, const char *value) +{ + struct ioband_device *dp = gp->c_banddev; + const char *val_str; + long id; + unsigned long flags; + int r; + + r = parse_group_param(value, &id, &val_str); + if (r) + return r; + + spin_lock_irqsave(&dp->g_lock, flags); + if (id != IOBAND_ID_ANY) { + gp = ioband_group_find(gp, id); + if (!gp) { + spin_unlock_irqrestore(&dp->g_lock, flags); + DMWARN("%s: id=%ld not found.", __func__, id); + return -EINVAL; + } + } + r = dp->g_set_param(gp, cmd, val_str); + spin_unlock_irqrestore(&dp->g_lock, flags); + return r; +} + +static int ioband_group_attach(struct ioband_group *head, int parent_id, + int id, const char *param) +{ + struct ioband_device *dp = head->c_banddev; + struct ioband_group *parent, *gp; + int r; + + if (id < 0) { + DMWARN("%s: invalid id:%d", __func__, id); + return -EINVAL; + } + if (!head->c_type->t_getid) { + DMWARN("%s: no ioband group type is specified", __func__); + return -EINVAL; + } + + /* Determines a parent ioband group */ + switch (parent_id) { + case 0: + /* Non-hierarchical configuration */ + parent = NULL; + break; + case 1: + /* The root of a tree, the parent is a default ioband group */ + parent = head; + break; + default: + /* The node in a tree. */ + parent = ioband_group_find(head, parent_id); + if (!parent) { + DMWARN("%s: parent group is not configured", __func__); + return -EINVAL; + } + break; + } + + gp = kzalloc(sizeof(struct ioband_group), GFP_KERNEL); + if (!gp) + return -ENOMEM; + + r = ioband_group_init(dp, head, parent, gp, id, param); + if (r < 0) { + kfree(gp); + return r; + } + return 0; +} + +static int ioband_group_detach(struct ioband_group *head, int id) +{ + struct ioband_device *dp = head->c_banddev; + struct ioband_group *gp; + unsigned long flags; + int r = 0; + + if (id < 0) { + DMWARN("%s: invalid id:%d", __func__, id); + return -EINVAL; + } + spin_lock_irqsave(&dp->g_lock, flags); + gp = ioband_group_find(head, id); + if (!gp) { + DMWARN("%s: invalid id:%d", __func__, id); + r = -EINVAL; + goto out; + } + + if (!list_empty(&gp->c_children)) { + DMWARN("%s: group has children", __func__); + r = -EBUSY; + goto out; + } + + /* + * Todo: Calling suspend_ioband_device() before releasing the + * ioband group has a large overhead. Need improvement. + */ + suspend_ioband_device(dp, flags, 0); + ioband_group_release(head, gp); + resume_ioband_device(dp); +out: + spin_unlock_irqrestore(&dp->g_lock, flags); + return r; +} + +/* + * Message parameters: + * "policy" <name> + * ex) + * "policy" "weight" + * "type" "none"|"pid"|"pgrp"|"node"|"cpuset"|"cgroup"|"user"|"gid" + * "io_throttle" <value> + * "io_limit" <value> + * "attach" <group id> + * "detach" <group id> + * "any-command" <group id>:<value> + * ex) + * "weight" 0:<value> + * "token" 24:<value> + */ +static int __ioband_message(struct dm_target *ti, unsigned argc, char **argv) +{ + struct ioband_group *gp = ti->private, *p; + struct ioband_device *dp = gp->c_banddev; + struct rb_node *node; + long val; + int r = 0; + unsigned long flags; + + if (argc == 1 && !strcmp(argv[0], "reset")) { + spin_lock_irqsave(&dp->g_lock, flags); + memset(&gp->c_stats, 0, sizeof(gp->c_stats)); + for (node = rb_first(&gp->c_group_root); node; + node = rb_next(node)) { + p = rb_entry(node, struct ioband_group, c_group_node); + memset(&p->c_stats, 0, sizeof(p->c_stats)); + } + spin_unlock_irqrestore(&dp->g_lock, flags); + return 0; + } + + if (argc != 2) { + DMWARN("Unrecognised band message received."); + return -EINVAL; + } + if (!strcmp(argv[0], "io_throttle")) { + r = strict_strtol(argv[1], 0, &val); + if (r || val < 0 || val > SHORT_MAX) + return -EINVAL; + if (val == 0) + val = DEFAULT_IO_THROTTLE; + spin_lock_irqsave(&dp->g_lock, flags); + if (val > dp->g_io_limit) { + spin_unlock_irqrestore(&dp->g_lock, flags); + return -EINVAL; + } + dp->g_io_throttle = val; + spin_unlock_irqrestore(&dp->g_lock, flags); + ioband_set_param(gp, argv[0], argv[1]); + return 0; + } else if (!strcmp(argv[0], "io_limit")) { + r = strict_strtol(argv[1], 0, &val); + if (r || val < 0 || val > SHORT_MAX) + return -EINVAL; + spin_lock_irqsave(&dp->g_lock, flags); + if (val == 0) { + struct request_queue *q; + + q = bdev_get_queue(gp->c_dev->bdev); + if (!q) { + spin_unlock_irqrestore(&dp->g_lock, flags); + return -ENXIO; + } + /* + * The block layer accepts I/O requests up to + * 50% over nr_requests when the requests are + * issued from a "batcher" process. + */ + val = (3 * q->nr_requests / 2); + } + if (val < dp->g_io_throttle) { + spin_unlock_irqrestore(&dp->g_lock, flags); + return -EINVAL; + } + dp->g_io_limit = val; + spin_unlock_irqrestore(&dp->g_lock, flags); + ioband_set_param(gp, argv[0], argv[1]); + return 0; + } else if (!strcmp(argv[0], "type")) { + return ioband_group_type_select(gp, argv[1]); + } else if (!strcmp(argv[0], "attach")) { + r = strict_strtol(argv[1], 0, &val); + if (r) + return r; + return ioband_group_attach(gp, 0, val, NULL); + } else if (!strcmp(argv[0], "detach")) { + r = strict_strtol(argv[1], 0, &val); + if (r) + return r; + return ioband_group_detach(gp, val); + } else if (!strcmp(argv[0], "policy")) { + r = policy_init(dp, argv[1], 0, &argv[2]); + return r; + } else { + /* message anycommand <group-id>:<value> */ + r = ioband_set_param(gp, argv[0], argv[1]); + if (r < 0) + DMWARN("Unrecognised band message received."); + return r; + } + return 0; +} + +static int ioband_message(struct dm_target *ti, unsigned argc, char **argv) +{ + int r; + + mutex_lock(&ioband_lock); + r = __ioband_message(ti, argc, argv); + mutex_unlock(&ioband_lock); + return r; +} + +static int ioband_merge(struct dm_target *ti, struct bvec_merge_data *bvm, + struct bio_vec *biovec, int max_size) +{ + struct ioband_group *gp = ti->private; + struct request_queue *q = bdev_get_queue(gp->c_dev->bdev); + + if (!q->merge_bvec_fn) + return max_size; + + bvm->bi_bdev = gp->c_dev->bdev; + bvm->bi_sector -= ti->begin; + + return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); +} + +static int ioband_iterate_devices(struct dm_target *ti, + iterate_devices_callout_fn fn, void *data) +{ + struct ioband_group *gp = ti->private; + + return fn(ti, gp->c_dev, 0, ti->len, data); +} + +static struct target_type ioband_target = { + .name = "ioband", + .module = THIS_MODULE, + .version = {1, 13, 0}, + .ctr = ioband_ctr, + .dtr = ioband_dtr, + .map = ioband_map, + .end_io = ioband_end_io, + .presuspend = ioband_presuspend, + .resume = ioband_resume, + .status = ioband_status, + .message = ioband_message, + .merge = ioband_merge, + .iterate_devices = ioband_iterate_devices, +}; + +static int __init dm_ioband_init(void) +{ + int r; + + r = dm_register_target(&ioband_target); + if (r < 0) + DMERR("register failed %d", r); + return r; +} + +static void __exit dm_ioband_exit(void) +{ + dm_unregister_target(&ioband_target); +} + +module_init(dm_ioband_init); +module_exit(dm_ioband_exit); + +MODULE_DESCRIPTION(DM_NAME " I/O bandwidth control"); +MODULE_AUTHOR("Hirokazu Takahashi, Ryo Tsuruta, Dong-Jae Kang"); +MODULE_LICENSE("GPL"); Index: linux-2.6.31/drivers/md/dm-ioband-policy.c =================================================================== --- /dev/null +++ linux-2.6.31/drivers/md/dm-ioband-policy.c @@ -0,0 +1,543 @@ +/* + * Copyright (C) 2008-2009 VA Linux Systems Japan K.K. + * + * I/O bandwidth control + * + * This file is released under the GPL. + */ +#include <linux/bio.h> +#include <linux/workqueue.h> +#include <linux/rbtree.h> +#include "dm.h" +#include "dm-ioband.h" + +/* + * The following functions determine when and which BIOs should + * be submitted to control the I/O flow. + * It is possible to add a new BIO scheduling policy with it. + */ + +/* + * Functions for weight balancing policy based on the number of I/Os. + */ +#define DEFAULT_WEIGHT 100 +#define DEFAULT_TOKENPOOL 2048 +#define DEFAULT_BUCKET 2 +#define IOBAND_IOPRIO_BASE 100 +#define TOKEN_BATCH_UNIT 20 +#define PROCEED_THRESHOLD 8 +#define LOCAL_ACTIVE_RATIO 8 +#define GLOBAL_ACTIVE_RATIO 16 +#define OVERCOMMIT_RATE 4 +#define WEIGHT_MAX 100 + +/* + * Calculate the effective number of tokens this group has. + */ +static int get_token(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + int token = gp->c_token; + int allowance = dp->g_epoch - gp->c_my_epoch; + + if (allowance) { + if (allowance > dp->g_carryover) + allowance = dp->g_carryover; + token += gp->c_token_initial * allowance; + } + if (is_group_down(gp)) + token += gp->c_token_initial * dp->g_carryover * 2; + + return token; +} + +/* + * Calculate the priority of a given group. + */ +static int iopriority(struct ioband_group *gp) +{ + return get_token(gp) * IOBAND_IOPRIO_BASE / gp->c_token_initial + 1; +} + +/* + * This function is called when all the active group on the same ioband + * device has used up their tokens. It makes a new global epoch so that + * all groups on this device will get freshly assigned tokens. + */ +static int make_global_epoch(struct ioband_device *dp) +{ + struct ioband_group *gp = dp->g_dominant; + + /* + * Don't make a new epoch if the dominant group still has a lot of + * tokens, except when the I/O load is low. + */ + if (gp) { + int iopri = iopriority(gp); + if (iopri * PROCEED_THRESHOLD > IOBAND_IOPRIO_BASE && + nr_issued(dp) >= dp->g_io_throttle) + return 0; + } + + dp->g_epoch++; + DMDEBUG("make_epoch %d", dp->g_epoch); + + /* The leftover tokens will be used in the next epoch. */ + dp->g_token_extra = dp->g_token_left; + if (dp->g_token_extra < 0) + dp->g_token_extra = 0; + dp->g_token_left = dp->g_token_bucket; + + dp->g_expired = NULL; + dp->g_dominant = NULL; + + return 1; +} + +/* + * This function is called when this group has used up its own tokens. + * It will check whether it's possible to make a new epoch of this group. + */ +static inline int make_epoch(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + int allowance = dp->g_epoch - gp->c_my_epoch; + + if (!allowance) + return 0; + if (allowance > dp->g_carryover) + allowance = dp->g_carryover; + gp->c_my_epoch = dp->g_epoch; + return allowance; +} + +/* + * Check whether this group has tokens to issue an I/O. Return 0 if it + * doesn't have any, otherwise return the priority of this group. + */ +static int is_token_left(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + int allowance; + int delta; + int extra; + + if (gp->c_token > 0) + return iopriority(gp); + + if (is_group_down(gp)) { + gp->c_token = gp->c_token_initial; + return iopriority(gp); + } + allowance = make_epoch(gp); + if (!allowance) + return 0; + /* + * If this group has the right to get tokens for several epochs, + * give all of them to the group here. + */ + delta = gp->c_token_initial * allowance; + dp->g_token_left -= delta; + /* + * Give some extra tokens to this group when there have left unused + * tokens on this ioband device from the previous epoch. + */ + extra = dp->g_token_extra * gp->c_token_initial / + (dp->g_token_bucket - dp->g_token_extra / 2); + delta += extra; + gp->c_token += delta; + gp->c_consumed = 0; + + if (gp == dp->g_current) + dp->g_yield_mark += delta; + DMDEBUG("refill token: gp:%p token:%d->%d extra(%d) allowance(%d)", + gp, gp->c_token - delta, gp->c_token, extra, allowance); + if (gp->c_token > 0) + return iopriority(gp); + DMDEBUG("refill token: yet empty gp:%p token:%d", gp, gp->c_token); + return 0; +} + +/* + * Use tokens to issue an I/O. After the operation, the number of tokens left + * on this group may become negative value, which will be treated as debt. + */ +static int consume_token(struct ioband_group *gp, int count, int flag) +{ + struct ioband_device *dp = gp->c_banddev; + + if (gp->c_consumed * LOCAL_ACTIVE_RATIO < gp->c_token_initial && + gp->c_consumed * GLOBAL_ACTIVE_RATIO < dp->g_token_bucket) { + ; /* Do nothing unless this group is really active. */ + } else if (!dp->g_dominant || + get_token(gp) > get_token(dp->g_dominant)) { + /* + * Regard this group as the dominant group on this + * ioband device when it has larger number of tokens + * than those of the previous one. + */ + dp->g_dominant = gp; + } + if (dp->g_epoch == gp->c_my_epoch && + gp->c_token > 0 && gp->c_token - count <= 0) { + /* Remember the last group which used up its own tokens. */ + dp->g_expired = gp; + if (dp->g_dominant == gp) + dp->g_dominant = NULL; + } + + if (gp != dp->g_current) { + /* This group is the current already. */ + dp->g_current = gp; + dp->g_yield_mark = + gp->c_token - (TOKEN_BATCH_UNIT << dp->g_token_unit); + } + gp->c_token -= count; + gp->c_consumed += count; + if (gp->c_token <= dp->g_yield_mark && !(flag & IOBAND_URGENT)) { + /* + * Return-value 1 means that this policy requests dm-ioband + * to give a chance to another group to be selected since + * this group has already issued enough amount of I/Os. + */ + dp->g_current = NULL; + return R_YIELD; + } + /* + * Return-value 0 means that this policy allows dm-ioband to select + * this group to issue I/Os without a break. + */ + return R_OK; +} + +/* + * Consume one token on each I/O. + */ +static int prepare_token(struct ioband_group *gp, struct bio *bio, int flag) +{ + return consume_token(gp, 1, flag); +} + +/* + * Check if this group is able to receive a new bio. + */ +static int is_queue_full(struct ioband_group *gp) +{ + return gp->c_blocked >= gp->c_limit; +} + +static void __set_weight(struct ioband_group *gp, int weight_total, + int token_bucket, int limit_bucket) +{ + int token, limit; + + if (weight_total > 0) { + token = token_bucket * gp->c_weight / weight_total; + if (token < 1) + token = 1; + limit = limit_bucket * gp->c_weight / weight_total; + if (limit < 1) + limit = 1; + + /* + * In the hierarchical configuration, + * child's tokens are distributed from the parent. + */ + if (gp->c_parent) { + gp->c_parent->c_token_initial -= token; + if (gp->c_parent->c_token_initial < 1) + gp->c_parent->c_token_initial = 1; + + gp->c_parent->c_limit -= limit / OVERCOMMIT_RATE; + if (gp->c_parent->c_limit < 1) + gp->c_parent->c_limit = 1; + } + } else + token = limit = 1; + + gp->c_token = gp->c_token_initial = gp->c_token_bucket = token; + gp->c_limit_bucket = limit; + gp->c_limit = limit / OVERCOMMIT_RATE; + if (gp->c_limit < 1) + gp->c_limit = 1; +} + +static int set_weight(struct ioband_group *group, int new) +{ + struct ioband_device *dp = group->c_banddev; + struct ioband_group *parent = group->c_parent, *gp; + struct list_head *siblings; + int weight_total = 0, token_bucket, limit; + + group->c_weight = new; + + if (!parent) { + siblings = &dp->g_root_groups; + token_bucket = dp->g_token_bucket; + limit = dp->g_io_limit * 2; + } else { + siblings = &parent->c_children; + token_bucket = parent->c_token_bucket; + limit = parent->c_limit_bucket; + } + + list_for_each_entry(gp, siblings, c_sibling) + weight_total += gp->c_weight; + + if (parent) { + /* + * In the hierarchical configuration, each child's + * weight is evaluated as a percentage of its parent's + * bandwidth. + */ + if (weight_total > WEIGHT_MAX) + return -EINVAL; + weight_total = WEIGHT_MAX; + } + + list_for_each_entry(parent, siblings, c_sibling) { + struct ioband_group *this_parent = parent; + struct list_head *next; + + __set_weight(parent, weight_total, token_bucket, limit); + + repeat: + next = this_parent->c_children.next; + resume: + while (next != &this_parent->c_children) { + /* Descend the hierarchy */ + struct list_head *tmp = next; + + gp = list_entry(tmp, struct ioband_group, c_sibling); + next = tmp->next; + + __set_weight(gp, WEIGHT_MAX, + this_parent->c_token_bucket, + this_parent->c_limit_bucket); + + if (!list_empty(&gp->c_children)) { + this_parent = gp; + goto repeat; + } + } + + if (this_parent != parent) { + /* Ascend and resume the search */ + next = this_parent->c_sibling.next; + this_parent = this_parent->c_parent; + goto resume; + } + } + + return 0; +} + +static void init_token_bucket(struct ioband_device *dp, + int token_bucket, int carryover) +{ + if (!token_bucket) + dp->g_token_bucket = (dp->g_io_limit * 2 * DEFAULT_BUCKET) << + dp->g_token_unit; + else + dp->g_token_bucket = token_bucket; + if (!carryover) + dp->g_carryover = (DEFAULT_TOKENPOOL << dp->g_token_unit) / + dp->g_token_bucket; + else + dp->g_carryover = carryover; + if (dp->g_carryover < 1) + dp->g_carryover = 1; + dp->g_token_left = 0; +} + +static int policy_weight_param(struct ioband_group *gp, + const char *cmd, const char *value) +{ + struct ioband_device *dp = gp->c_banddev; + long val = 0; + int r = 0, err = 0; + + if (value) + err = strict_strtol(value, 0, &val); + + if (!strcmp(cmd, "weight")) { + if (!value) + r = set_weight(gp, DEFAULT_WEIGHT); + else if (!err && 0 < val && val <= SHORT_MAX) + r = set_weight(gp, val); + else + r = -EINVAL; + } else if (!strcmp(cmd, "token")) { + if (!err && 0 <= val && val <= INT_MAX) { + init_token_bucket(dp, val, 0); + set_weight(gp, gp->c_weight); + dp->g_token_extra = 0; + } else + r = -EINVAL; + } else if (!strcmp(cmd, "carryover")) { + if (!err && 0 <= val && val <= INT_MAX) { + init_token_bucket(dp, dp->g_token_bucket, val); + set_weight(gp, gp->c_weight); + dp->g_token_extra = 0; + } else + r = -EINVAL; + } else if (!strcmp(cmd, "io_limit")) { + init_token_bucket(dp, 0, 0); + set_weight(gp, gp->c_weight); + } else { + r = -EINVAL; + } + return r; +} + +static int policy_weight_ctr(struct ioband_group *gp, const char *arg) +{ + struct ioband_device *dp = gp->c_banddev; + + gp->c_my_epoch = dp->g_epoch; + gp->c_weight = 0; + gp->c_consumed = 0; + return policy_weight_param(gp, "weight", arg); +} + +static void policy_weight_dtr(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + set_weight(gp, 0); + dp->g_dominant = NULL; + dp->g_expired = NULL; +} + +static void policy_weight_show(struct ioband_group *gp, int *szp, + char *result, unsigned maxlen) +{ + struct ioband_group *p; + struct ioband_device *dp = gp->c_banddev; + struct rb_node *node; + int sz = *szp; /* used in DMEMIT() */ + + DMEMIT(" %d :%d", dp->g_token_bucket, gp->c_weight); + + for (node = rb_first(&gp->c_group_root); node; node = rb_next(node)) { + p = rb_entry(node, struct ioband_group, c_group_node); + DMEMIT(" %d:%d", p->c_id, p->c_weight); + } + *szp = sz; +} + +/* + * <Method> <description> + * g_can_submit : To determine whether a given group has the right to + * submit BIOs. The larger the return value the higher the + * priority to submit. Zero means it has no right. + * g_prepare_bio : Called right before submitting each BIO. + * g_restart_bios : Called if this ioband device has some BIOs blocked but none + * of them can be submitted now. This method has to + * reinitialize the data to restart to submit BIOs and return + * 0 or 1. + * The return value 0 means that it has become able to submit + * them now so that this ioband device will continue its work. + * The return value 1 means that it is still unable to submit + * them so that this device will stop its work. And this + * policy module has to reactivate the device when it gets + * to be able to submit BIOs. + * g_hold_bio : To hold a given BIO until it is submitted. + * The default function is used when this method is undefined. + * g_pop_bio : To select and get the best BIO to submit. + * g_group_ctr : To initalize the policy own members of struct ioband_group. + * g_group_dtr : Called when struct ioband_group is removed. + * g_set_param : To update the policy own date. + * The parameters can be passed through "dmsetup message" + * command. + * g_should_block : Called every time this ioband device receive a BIO. + * Return 1 if a given group can't receive any more BIOs, + * otherwise return 0. + * g_show : Show the configuration. + */ +static int policy_weight_init(struct ioband_device *dp, int argc, char **argv) +{ + long val; + int r = 0; + + if (argc < 1) + val = 0; + else { + r = strict_strtol(argv[0], 0, &val); + if (r || val < 0 || val > INT_MAX) + return -EINVAL; + } + + dp->g_can_submit = is_token_left; + dp->g_prepare_bio = prepare_token; + dp->g_restart_bios = make_global_epoch; + dp->g_group_ctr = policy_weight_ctr; + dp->g_group_dtr = policy_weight_dtr; + dp->g_set_param = policy_weight_param; + dp->g_should_block = is_queue_full; + dp->g_show = policy_weight_show; + + dp->g_epoch = 0; + dp->g_weight_total = 0; + dp->g_current = NULL; + dp->g_dominant = NULL; + dp->g_expired = NULL; + dp->g_token_extra = 0; + dp->g_token_unit = 0; + init_token_bucket(dp, val, 0); + dp->g_token_left = dp->g_token_bucket; + + return 0; +} + +/* weight balancing policy based on the number of I/Os. --- End --- */ + +/* + * Functions for weight balancing policy based on I/O size. + * It just borrows a lot of functions from the regular weight balancing policy. + */ +static int iosize_prepare_token(struct ioband_group *gp, + struct bio *bio, int flag) +{ + /* Consume tokens depending on the size of a given bio. */ + return consume_token(gp, bio_sectors(bio), flag); +} + +static int policy_weight_iosize_init(struct ioband_device *dp, + int argc, char **argv) +{ + long val; + int r = 0; + + if (argc < 1) + val = 0; + else { + r = strict_strtol(argv[0], 0, &val); + if (r || val < 0 || val > INT_MAX) + return -EINVAL; + } + + r = policy_weight_init(dp, argc, argv); + if (r < 0) + return r; + + dp->g_prepare_bio = iosize_prepare_token; + dp->g_token_unit = PAGE_SHIFT - 9; + init_token_bucket(dp, val, 0); + dp->g_token_left = dp->g_token_bucket; + return 0; +} + +/* weight balancing policy based on I/O size. --- End --- */ + +static int policy_default_init(struct ioband_device *dp, int argc, char **argv) +{ + return policy_weight_init(dp, argc, argv); +} + +const struct ioband_policy_type dm_ioband_policy_type[] = { + { "default", policy_default_init }, + { "weight", policy_weight_init }, + { "weight-iosize", policy_weight_iosize_init }, + { "range-bw", policy_range_bw_init }, + { NULL, policy_default_init } +}; Index: linux-2.6.31/drivers/md/dm-ioband-type.c =================================================================== --- /dev/null +++ linux-2.6.31/drivers/md/dm-ioband-type.c @@ -0,0 +1,76 @@ +/* + * Copyright (C) 2008-2009 VA Linux Systems Japan K.K. + * + * I/O bandwidth control + * + * This file is released under the GPL. + */ +#include <linux/bio.h> +#include "dm.h" +#include "dm-ioband.h" + +/* + * Any I/O bandwidth can be divided into several bandwidth groups, each of
which + * has its own unique ID. The following functions are called to determine + * which group a given BIO belongs to and return the ID of the group. + */ + +/* ToDo: unsigned long value would be better for group ID */ + +static int ioband_process_id(struct bio *bio) +{ + /* + * This function will work for KVM and Xen. + */ + return (int)current->tgid; +} + +static int ioband_process_group(struct bio *bio) +{ + return (int)task_pgrp_nr(current); +} + +static int ioband_uid(struct bio *bio) +{ + return (int)current_uid(); +} + +static int ioband_gid(struct bio *bio) +{ + return (int)current_gid(); +} + +static int ioband_cpuset(struct bio *bio) +{ + return 0; /* not implemented yet */ +} + +static int ioband_node(struct bio *bio) +{ + return 0; /* not implemented yet */ +} + +static int ioband_cgroup(struct bio *bio) +{ + /* + * This function should return the ID of the cgroup which + * issued "bio". The ID of the cgroup which the current + * process belongs to won't be suitable ID for this purpose, + * since some BIOs will be handled by kernel threads like aio + * or pdflush on behalf of the process requesting the BIOs. + */ + return 0; /* not implemented yet */ +} + +const struct ioband_group_type dm_ioband_group_type[] = { + { "none", NULL }, + { "pgrp", ioband_process_group }, + { "pid", ioband_process_id }, + { "node", ioband_node }, + { "cpuset", ioband_cpuset }, + { "cgroup", ioband_cgroup }, + { "user", ioband_uid }, + { "uid", ioband_uid }, + { "gid", ioband_gid }, + { NULL, NULL} +}; Index: linux-2.6.31/drivers/md/dm-ioband.h =================================================================== --- /dev/null +++ linux-2.6.31/drivers/md/dm-ioband.h @@ -0,0 +1,231 @@ +/* + * Copyright (C) 2008-2009 VA Linux Systems Japan K.K. + * + * I/O bandwidth control + * + * This file is released under the GPL. + */ + +#ifndef DM_IOBAND_H +#define DM_IOBAND_H + +#include <linux/version.h> +#include <linux/wait.h> + +#define DM_MSG_PREFIX "ioband" + +#define DEFAULT_IO_THROTTLE 4 +#define IOBAND_NAME_MAX 31 +#define IOBAND_ID_ANY (-1) +#define POLICY_PARAM_START 6 +#define POLICY_PARAM_DELIM "=:," + +#define MAX_BW_OVER 1 +#define MAX_BW_UNDER 0 +#define NO_IO_MODE 4 + +#define TIME_COMPENSATOR 10 + +struct ioband_group; + +struct ioband_device { + struct list_head g_groups; + struct delayed_work g_conductor; + struct workqueue_struct *g_ioband_wq; + struct bio_list g_urgent_bios; + int g_io_throttle; + int g_io_limit; + int g_issued[2]; + int g_blocked; + spinlock_t g_lock; + wait_queue_head_t g_waitq; + wait_queue_head_t g_waitq_suspend; + wait_queue_head_t g_waitq_flush; + + int g_ref; + struct list_head g_list; + struct list_head g_root_groups; + int g_flags; + char g_name[IOBAND_NAME_MAX + 1]; + const struct ioband_policy_type *g_policy; + + /* policy dependent */ + int (*g_can_submit) (struct ioband_group *); + int (*g_prepare_bio) (struct ioband_group *, struct bio *, int); + int (*g_restart_bios) (struct ioband_device *); + void (*g_hold_bio) (struct ioband_group *, struct bio *); + struct bio *(*g_pop_bio) (struct ioband_group *); + int (*g_group_ctr) (struct ioband_group *, const char *); + void (*g_group_dtr) (struct ioband_group *); + int (*g_set_param) (struct ioband_group *, const char *, const char *); + int (*g_should_block) (struct ioband_group *); + void (*g_show) (struct ioband_group *, int *, char *, unsigned); + + /* members for weight balancing policy */ + int g_epoch; + int g_weight_total; + /* the number of tokens which can be used in every epoch */ + int g_token_bucket; + /* how many epochs tokens can be carried over */ + int g_carryover; + /* how many tokens should be used for one page-sized I/O */ + int g_token_unit; + /* the last group which used a token */ + struct ioband_group *g_current; + /* give another group a chance to be scheduled when the rest + of tokens of the current group reaches this mark */ + int g_yield_mark; + /* the latest group which used up its tokens */ + struct ioband_group *g_expired; + /* the group which has the largest number of tokens in the + active groups */ + struct ioband_group *g_dominant; + /* the number of unused tokens in this epoch */ + int g_token_left; + /* left-over tokens from the previous epoch */ + int g_token_extra; + + /* members for range-bw policy */ + int g_min_bw_total; + int g_max_bw_total; + unsigned long g_next_time_period; + int g_time_period_expired; + struct ioband_group *g_running_gp; + int g_total_min_bw_token; + int g_consumed_min_bw_token; + int g_io_mode; + +}; + +struct ioband_group { + struct list_head c_list; + struct list_head c_sibling; + struct list_head c_children; + struct ioband_group *c_parent; + struct ioband_device *c_banddev; + struct dm_dev *c_dev; + struct dm_target *c_target; + struct bio_list c_blocked_bios; + struct bio_list c_prio_bios; + struct rb_root c_group_root; + struct rb_node c_group_node; + int c_id; /* should be unsigned long or unsigned long long */ + char c_name[IOBAND_NAME_MAX + 1]; /* rfu */ + int c_blocked; + int c_prio_blocked; + wait_queue_head_t c_waitq; + int c_flags; + struct disk_stats c_stats; /* hold rd/wr status */ + const struct ioband_group_type *c_type; + + /* members for weight balancing policy */ + int c_weight; + int c_my_epoch; + int c_token; + int c_token_initial; + int c_token_bucket; + int c_limit; + int c_limit_bucket; + int c_consumed; + + /* rfu */ + /* struct bio_list c_ordered_tag_bios; */ + + /* members for range-bw policy */ + wait_queue_head_t c_max_bw_over_waitq; + struct timer_list *c_timer; + int timer_set; + int c_min_bw; + int c_max_bw; + int c_time_slice_expired; + int c_min_bw_token; + int c_max_bw_token; + int c_consumed_min_bw_token; + int c_is_over_max_bw; + int c_io_mode; + unsigned long c_time_slice; + unsigned long c_time_slice_start; + unsigned long c_time_slice_end; + int c_wait_p_count; + +}; + +#define IOBAND_URGENT 1 + +#define DEV_BIO_BLOCKED 1 +#define DEV_SUSPENDED 2 + +#define set_device_blocked(dp) ((dp)->g_flags |= DEV_BIO_BLOCKED) +#define clear_device_blocked(dp) ((dp)->g_flags &= ~DEV_BIO_BLOCKED) +#define is_device_blocked(dp) ((dp)->g_flags & DEV_BIO_BLOCKED) + +#define set_device_suspended(dp) ((dp)->g_flags |= DEV_SUSPENDED) +#define clear_device_suspended(dp) ((dp)->g_flags &= ~DEV_SUSPENDED) +#define is_device_suspended(dp) ((dp)->g_flags & DEV_SUSPENDED) + +#define IOG_PRIO_BIO_SYNC 1 +#define IOG_PRIO_QUEUE 2 +#define IOG_BIO_BLOCKED 4 +#define IOG_GOING_DOWN 8 +#define IOG_SUSPENDED 16 +#define IOG_NEED_UP 32 + +#define R_OK 0 +#define R_BLOCK 1 +#define R_YIELD 2 + +#define set_group_blocked(gp) ((gp)->c_flags |= IOG_BIO_BLOCKED) +#define clear_group_blocked(gp) ((gp)->c_flags &= ~IOG_BIO_BLOCKED) +#define is_group_blocked(gp) ((gp)->c_flags & IOG_BIO_BLOCKED) + +#define set_group_down(gp) ((gp)->c_flags |= IOG_GOING_DOWN) +#define clear_group_down(gp) ((gp)->c_flags &= ~IOG_GOING_DOWN) +#define is_group_down(gp) ((gp)->c_flags & IOG_GOING_DOWN) + +#define set_group_suspended(gp) ((gp)->c_flags |= IOG_SUSPENDED) +#define clear_group_suspended(gp) ((gp)->c_flags &= ~IOG_SUSPENDED) +#define is_group_suspended(gp) ((gp)->c_flags & IOG_SUSPENDED) + +#define set_group_need_up(gp) ((gp)->c_flags |= IOG_NEED_UP) +#define clear_group_need_up(gp) ((gp)->c_flags &= ~IOG_NEED_UP) +#define group_need_up(gp) ((gp)->c_flags & IOG_NEED_UP) + +#define set_prio_async(gp) ((gp)->c_flags |= IOG_PRIO_QUEUE) +#define clear_prio_async(gp) ((gp)->c_flags &= ~IOG_PRIO_QUEUE) +#define is_prio_async(gp) \ + ((gp)->c_flags & (IOG_PRIO_QUEUE|IOG_PRIO_BIO_SYNC) == IOG_PRIO_QUEUE) + +#define set_prio_sync(gp) \ + ((gp)->c_flags |= (IOG_PRIO_QUEUE|IOG_PRIO_BIO_SYNC)) +#define clear_prio_sync(gp) \ + ((gp)->c_flags &= ~(IOG_PRIO_QUEUE|IOG_PRIO_BIO_SYNC)) +#define is_prio_sync(gp) \ + ((gp)->c_flags & (IOG_PRIO_QUEUE|IOG_PRIO_BIO_SYNC) == \ + (IOG_PRIO_QUEUE|IOG_PRIO_BIO_SYNC)) + +#define set_prio_queue(gp, sync) \ + ((gp)->c_flags |= (IOG_PRIO_QUEUE|sync)) +#define clear_prio_queue(gp) clear_prio_sync(gp) +#define is_prio_queue(gp) ((gp)->c_flags & IOG_PRIO_QUEUE) +#define prio_queue_sync(gp) ((gp)->c_flags & IOG_PRIO_BIO_SYNC) + +#define nr_issued(dp) \ + ((dp)->g_issued[BLK_RW_SYNC] + (dp)->g_issued[BLK_RW_ASYNC]) + +struct ioband_policy_type { + const char *p_name; + int (*p_policy_init) (struct ioband_device *, int, char **); +}; + +extern const struct ioband_policy_type dm_ioband_policy_type[]; + +struct ioband_group_type { + const char *t_name; + int (*t_getid) (struct bio *); +}; + +extern const struct ioband_group_type dm_ioband_group_type[]; + +extern int policy_range_bw_init(struct ioband_device *, int, char **); + +#endif /* DM_IOBAND_H */ Index: linux-2.6.31/drivers/md/dm-ioband-rangebw.c =================================================================== --- /dev/null +++ linux-2.6.31/drivers/md/dm-ioband-rangebw.c @@ -0,0 +1,669 @@ +/* + * dm-ioband-rangebw.c + * + * This is a I/O control policy to support the Range Bandwidth in Disk I/O. + * And this policy is for dm-ioband controller by Ryo Tsuruta, + * Hirokazu Takahashi + * + * Copyright (C) 2008 - 2011 + * Electronics and Telecommunications Research Institute(ETRI) + * + * This program is free software. you can redistribute it and/or modify + * it under the terms of the GNU General Public License(GPL) as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + * + * Contact Information: + * Dong-Jae, Kang <djk@etri.re.kr>, Chei-Yol,Kim <gau@etri.re.kr>, + * Sung-In,Jung <sij@etri.re.kr> + */ + +#include <linux/bio.h> +#include <linux/workqueue.h> +#include <linux/rbtree.h> +#include <linux/jiffies.h> +#include <linux/random.h> +#include <linux/time.h> +#include <linux/timer.h> +#include "dm.h" +#include "md.h" +#include "dm-ioband.h" + +static void range_bw_timeover(unsigned long); +static void range_bw_timer_register(struct timer_list *, + unsigned long, unsigned long); + +/* + * Functions for Range Bandwidth(range-bw) policy based on + * the time slice and token. + */ +#define DEFAULT_BUCKET 2 +#define DEFAULT_TOKENPOOL 2048 + +#define TIME_SLICE_EXPIRED 1 +#define TIME_SLICE_NOT_EXPIRED 0 + +#define MINBW_IO_MODE 0 +#define LEFTOVER_IO_MODE 1 +#define RANGE_IO_MODE 2 +#define DEFAULT_IO_MODE 3 +#define NO_IO_MODE 4 + +#define MINBW_PRIO_BASE 10 +#define OVER_IO_RATE 4 + +#define DEFAULT_RANGE_BW "0:0" +#define DEFAULT_MIN_BW 0 +#define DEFAULT_MAX_BW 0 + +static const int time_slice_base = HZ / 10; +static const int range_time_slice_base = HZ / 50; +static void do_nothing(void) {} +/* + * g_restart_bios function for range-bw policy + */ +static int range_bw_restart_bios(struct ioband_device *dp) +{ + return 1; +} + +/* + * Allocate the time slice when IO mode is MINBW_IO_MODE, + * RANGE_IO_MODE or LEFTOVER_IO_MODE + */ +static int set_time_slice(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + int dp_io_mode, gp_io_mode; + unsigned long now = jiffies; + + dp_io_mode = dp->g_io_mode; + gp_io_mode = gp->c_io_mode; + + gp->c_time_slice_start = now; + + if (dp_io_mode == LEFTOVER_IO_MODE) { + gp->c_time_slice_end = now + gp->c_time_slice; + return 0; + } + + if (gp_io_mode == MINBW_IO_MODE) + gp->c_time_slice_end = now + gp->c_time_slice; + else if (gp_io_mode == RANGE_IO_MODE) + gp->c_time_slice_end = now + range_time_slice_base; + else if (gp_io_mode == DEFAULT_IO_MODE) + gp->c_time_slice_end = now + time_slice_base; + else if (gp_io_mode == NO_IO_MODE) { + gp->c_time_slice_end = 0; + gp->c_time_slice_expired = TIME_SLICE_EXPIRED; + return 0; + } + + gp->c_time_slice_expired = TIME_SLICE_NOT_EXPIRED; + + return 0; +} + +/* + * Calculate the priority of given ioband_group + */ +static int range_bw_priority(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + int prio = 0; + + if (dp->g_io_mode == LEFTOVER_IO_MODE) { + prio = random32() % MINBW_PRIO_BASE; + if (prio == 0) + prio = 1; + } else if (gp->c_io_mode == MINBW_IO_MODE) { + prio = (gp->c_min_bw_token - gp->c_consumed_min_bw_token) * + MINBW_PRIO_BASE; + } else if (gp->c_io_mode == DEFAULT_IO_MODE) { + prio = MINBW_PRIO_BASE; + } else if (gp->c_io_mode == RANGE_IO_MODE) { + prio = MINBW_PRIO_BASE / 2; + } else { + prio = 0; + } + + return prio; +} + +/* + * Check whether this group has right to issue an I/O in range-bw policy mode. + * Return 0 if it doesn't have right, otherwise return the non-zero value. + */ +static int has_right_to_issue(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + int prio; + + if (gp->c_prio_blocked > 0 || gp->c_blocked - gp->c_prio_blocked > 0) { + prio = range_bw_priority(gp); + if (prio <= 0) + return 1; + return prio; + } + + if (gp == dp->g_running_gp) { + + if (gp->c_time_slice_expired == TIME_SLICE_EXPIRED) { + + gp->c_time_slice_expired = TIME_SLICE_NOT_EXPIRED; + gp->c_time_slice_end = 0; + + return 0; + } + + if (gp->c_time_slice_end == 0) + set_time_slice(gp); + + return range_bw_priority(gp); + + } + + dp->g_running_gp = gp; + set_time_slice(gp); + + return range_bw_priority(gp); +} + +/* + * Reset all variables related with range-bw token and time slice + */ +static int reset_range_bw_token(struct ioband_group *gp, unsigned long now) +{ + struct ioband_device *dp = gp->c_banddev; + struct ioband_group *p; + + list_for_each_entry(p, &dp->g_groups, c_list) { + p->c_consumed_min_bw_token = 0; + p->c_is_over_max_bw = MAX_BW_UNDER; + if (p->c_io_mode != DEFAULT_IO_MODE) + p->c_io_mode = MINBW_IO_MODE; + } + + dp->g_consumed_min_bw_token = 0; + + dp->g_next_time_period = now + HZ; + dp->g_time_period_expired = TIME_SLICE_NOT_EXPIRED; + dp->g_io_mode = MINBW_IO_MODE; + + list_for_each_entry(p, &dp->g_groups, c_list) { + if (waitqueue_active(&p->c_max_bw_over_waitq)) + wake_up_all(&p->c_max_bw_over_waitq); + } + return 0; +} + +/* + * Use tokens(Increase the number of consumed token) to issue an I/O + * for guranteeing the range-bw. and check the expiration of local and + * global time slice, and overflow of max bw + */ +static int range_bw_consume_token(struct ioband_group *gp, int count, int flag) +{ + struct ioband_device *dp = gp->c_banddev; + struct ioband_group *p; + unsigned long now = jiffies; + + dp->g_current = gp; + + if (dp->g_next_time_period == 0) { + dp->g_next_time_period = now + HZ; + dp->g_time_period_expired = TIME_SLICE_NOT_EXPIRED; + } + + if (time_after(now, dp->g_next_time_period)) { + reset_range_bw_token(gp, now); + } else { + gp->c_consumed_min_bw_token += count; + dp->g_consumed_min_bw_token += count; + + if (gp->c_max_bw > 0 && gp->c_consumed_min_bw_token >= + gp->c_max_bw_token) { + gp->c_is_over_max_bw = MAX_BW_OVER; + gp->c_io_mode = NO_IO_MODE; + return R_YIELD; + } + + if (gp->c_io_mode != RANGE_IO_MODE && gp->c_min_bw_token <= + gp->c_consumed_min_bw_token) { + gp->c_io_mode = RANGE_IO_MODE; + + if (dp->g_total_min_bw_token <= + dp->g_consumed_min_bw_token) { + list_for_each_entry(p, &dp->g_groups, c_list) { + if (p->c_io_mode != RANGE_IO_MODE && + p->c_io_mode != DEFAULT_IO_MODE) + goto out; + } + + if (dp->g_io_mode == MINBW_IO_MODE) + dp->g_io_mode = LEFTOVER_IO_MODE; + out:; + } + } + } + + if (gp->c_time_slice_end != 0 && + time_after(now, gp->c_time_slice_end)) { + gp->c_time_slice_expired = TIME_SLICE_EXPIRED; + return R_YIELD; + } + + return R_OK; +} + +static int is_no_io_mode(struct ioband_group *gp) +{ + if (gp->c_io_mode == NO_IO_MODE) + return 1; + + return 0; +} + +/* + * Check if this group is able to receive a new bio. + * in range bw policy, we only check that ioband device should be blocked + */ +static int range_bw_queue_full(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + unsigned long now, time_step; + + if (is_no_io_mode(gp)) { + now = jiffies; + if (time_after(dp->g_next_time_period, now)) { + time_step = dp->g_next_time_period - now; + range_bw_timer_register(gp->c_timer, + (time_step + TIME_COMPENSATOR), + (unsigned long)gp); + wait_event_lock_irq(gp->c_max_bw_over_waitq, + !is_no_io_mode(gp), + dp->g_lock, do_nothing()); + } + } + + return (gp->c_blocked >= gp->c_limit); +} + +/* + * Convert the bw valuse to the number of bw token + * bw : Kbyte unit bandwidth + * token_base : the number of tokens used for one 1Kbyte-size IO + * -- Attention : Currently, We support the 512byte or 1Kbyte per 1 token + */ +static int convert_bw_to_token(int bw, int token_unit) +{ + int token; + int token_base; + + token_base = (1 << token_unit) / 4; + token = bw * token_base; + + return token; +} + + +/* + * Allocate the time slice for MINBW_IO_MODE to each group + */ +static void range_bw_time_slice_init(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + struct ioband_group *p; + + list_for_each_entry(p, &dp->g_groups, c_list) { + + if (dp->g_min_bw_total == 0) + p->c_time_slice = time_slice_base; + else + p->c_time_slice = time_slice_base + + ((time_slice_base * + ((p->c_min_bw + p->c_max_bw) / 2)) / + dp->g_min_bw_total); + } +} + +/* + * Allocate the range_bw and range_bw_token to the given group + */ +static void set_range_bw(struct ioband_group *gp, int new_min, int new_max) +{ + struct ioband_device *dp = gp->c_banddev; + struct ioband_group *p; + int token_unit; + + dp->g_min_bw_total += (new_min - gp->c_min_bw); + gp->c_min_bw = new_min; + + dp->g_max_bw_total += (new_max - gp->c_max_bw); + gp->c_max_bw = new_max; + + if (new_min) + gp->c_io_mode = MINBW_IO_MODE; + else + gp->c_io_mode = DEFAULT_IO_MODE; + + range_bw_time_slice_init(gp); + + token_unit = dp->g_token_unit; + gp->c_min_bw_token = convert_bw_to_token(new_min, token_unit); + dp->g_total_min_bw_token = + convert_bw_to_token(dp->g_min_bw_total, token_unit); + + gp->c_max_bw_token = convert_bw_to_token(new_max, token_unit); + + if (dp->g_min_bw_total == 0) { + list_for_each_entry(p, &dp->g_groups, c_list) + p->c_limit = 1; + } else { + list_for_each_entry(p, &dp->g_groups, c_list) { + p->c_limit = dp->g_io_limit * 2 * p->c_min_bw / + dp->g_min_bw_total / OVER_IO_RATE + 1; + } + } + + return; +} + +/* + * Allocate the min_bw and min_bw_token to the given group + */ +static void set_min_bw(struct ioband_group *gp, int new) +{ + struct ioband_device *dp = gp->c_banddev; + struct ioband_group *p; + int token_unit; + + dp->g_min_bw_total += (new - gp->c_min_bw); + gp->c_min_bw = new; + + if (new) + gp->c_io_mode = MINBW_IO_MODE; + else + gp->c_io_mode = DEFAULT_IO_MODE; + + range_bw_time_slice_init(gp); + + token_unit = dp->g_token_unit; + gp->c_min_bw_token = convert_bw_to_token(gp->c_min_bw, token_unit); + dp->g_total_min_bw_token = + convert_bw_to_token(dp->g_min_bw_total, token_unit); + + if (dp->g_min_bw_total == 0) { + list_for_each_entry(p, &dp->g_groups, c_list) + p->c_limit = 1; + } else { + list_for_each_entry(p, &dp->g_groups, c_list) { + p->c_limit = dp->g_io_limit * 2 * p->c_min_bw / + dp->g_min_bw_total / OVER_IO_RATE + 1; + } + } + + return; +} + +/* + * Allocate the max_bw and max_bw_token to the pointed group + */ +static void set_max_bw(struct ioband_group *gp, int new) +{ + struct ioband_device *dp = gp->c_banddev; + int token_unit; + + token_unit = dp->g_token_unit; + + dp->g_max_bw_total += (new - gp->c_max_bw); + gp->c_max_bw = new; + gp->c_max_bw_token = convert_bw_to_token(new, token_unit); + + range_bw_time_slice_init(gp); + + return; + +} + +static void init_range_bw_token_bucket(struct ioband_device *dp, int val) +{ + dp->g_token_bucket = (dp->g_io_limit * 2 * DEFAULT_BUCKET) << + dp->g_token_unit; + if (!val) + val = DEFAULT_TOKENPOOL << dp->g_token_unit; + if (val < dp->g_token_bucket) + val = dp->g_token_bucket; + dp->g_carryover = val/dp->g_token_bucket; + dp->g_token_left = 0; +} + +static int policy_range_bw_param(struct ioband_group *gp, + const char *cmd, const char *value) +{ + long val = 0, min_val = DEFAULT_MIN_BW, max_val = DEFAULT_MAX_BW; + int r = 0, err = 0; + char *endp; + + if (value) { + min_val = simple_strtol(value, &endp, 0); + if (strchr(POLICY_PARAM_DELIM, *endp)) { + max_val = simple_strtol(endp + 1, &endp, 0); + if (*endp != '\0') + err++; + } else + err++; + } + + if (!strcmp(cmd, "range-bw")) { + if (!err && 0 <= min_val && + min_val <= (INT_MAX / 2) && 0 <= max_val && + max_val <= (INT_MAX / 2) && min_val <= max_val) + set_range_bw(gp, min_val, max_val); + else + r = -EINVAL; + } else if (!strcmp(cmd, "min-bw")) { + if (!err && 0 <= val && val <= (INT_MAX / 2)) + set_min_bw(gp, val); + else + r = -EINVAL; + } else if (!strcmp(cmd, "max-bw")) { + if ((!err && 0 <= val && val <= (INT_MAX / 2) && + gp->c_min_bw <= val) || val == 0) + set_max_bw(gp, val); + else + r = -EINVAL; + } else { + r = -EINVAL; + } + return r; +} + +static int policy_range_bw_ctr(struct ioband_group *gp, const char *arg) +{ + int ret; + + init_waitqueue_head(&gp->c_max_bw_over_waitq); + + gp->c_min_bw = 0; + gp->c_max_bw = 0; + gp->c_io_mode = DEFAULT_IO_MODE; + gp->c_time_slice_expired = TIME_SLICE_NOT_EXPIRED; + gp->c_min_bw_token = 0; + gp->c_max_bw_token = 0; + gp->c_consumed_min_bw_token = 0; + gp->c_is_over_max_bw = MAX_BW_UNDER; + gp->c_time_slice_start = 0; + gp->c_time_slice_end = 0; + gp->c_wait_p_count = 0; + + gp->c_time_slice = time_slice_base; + + gp->c_timer = kmalloc(sizeof(struct timer_list), GFP_KERNEL); + if (gp->c_timer == NULL) + return -EINVAL; + memset(gp->c_timer, 0, sizeof(struct timer_list)); + gp->timer_set = 0; + + ret = policy_range_bw_param(gp, "range-bw", arg); + + return ret; +} + +static void policy_range_bw_dtr(struct ioband_group *gp) +{ + struct ioband_device *dp = gp->c_banddev; + + gp->c_time_slice = 0; + set_range_bw(gp, 0, 0); + + dp->g_running_gp = NULL; + + if (gp->c_timer != NULL) { + del_timer(gp->c_timer); + kfree(gp->c_timer); + } +} + +static void policy_range_bw_show(struct ioband_group *gp, int *szp, + char *result, unsigned int maxlen) +{ + struct ioband_group *p; + struct ioband_device *dp = gp->c_banddev; + struct rb_node *node; + int sz = *szp; /* used in DMEMIT() */ + + DMEMIT(" %d :%d:%d", dp->g_token_bucket * dp->g_carryover, + gp->c_min_bw, gp->c_max_bw); + + for (node = rb_first(&gp->c_group_root); node; node = rb_next(node)) { + p = rb_entry(node, struct ioband_group, c_group_node); + DMEMIT(" %d:%d:%d", p->c_id, p->c_min_bw, p->c_max_bw); + } + *szp = sz; +} + +static int range_bw_prepare_token(struct ioband_group *gp, + struct bio *bio, int flag) +{ + struct ioband_device *dp = gp->c_banddev; + int unit; + int bio_count; + int token_count = 0; + + unit = (1 << dp->g_token_unit); + bio_count = bio_sectors(bio); + + if (unit == 8) + token_count = bio_count; + else if (unit == 4) + token_count = bio_count / 2; + else if (unit == 2) + token_count = bio_count / 4; + else if (unit == 1) + token_count = bio_count / 8; + + return range_bw_consume_token(gp, token_count, flag); +} + +static void range_bw_timer_register(struct timer_list *ptimer, + unsigned long timeover, unsigned long gp) +{ + struct ioband_group *group = (struct ioband_group *)gp; + + if (group->timer_set == 0) { + init_timer(ptimer); + ptimer->expires = get_jiffies_64() + timeover; + ptimer->data = gp; + ptimer->function = range_bw_timeover; + add_timer(ptimer); + group->timer_set = 1; + } +} + +/* + * Timer Handler function to protect the all processes's hanging in + * lower min-bw configuration + */ +static void range_bw_timeover(unsigned long gp) +{ + struct ioband_group *group = (struct ioband_group *)gp; + + if (group->c_is_over_max_bw == MAX_BW_OVER) + group->c_is_over_max_bw = MAX_BW_UNDER; + + if (group->c_io_mode == NO_IO_MODE) + group->c_io_mode = MINBW_IO_MODE; + + if (waitqueue_active(&group->c_max_bw_over_waitq)) + wake_up_all(&group->c_max_bw_over_waitq); + + group->timer_set = 0; +} + +/* + * <Method> <description> + * g_can_submit : To determine whether a given group has the right to + * submit BIOs. The larger the return value the higher the + * priority to submit. Zero means it has no right. + * g_prepare_bio : Called right before submitting each BIO. + * g_restart_bios : Called if this ioband device has some BIOs blocked but none + * of them can be submitted now. This method has to + * reinitialize the data to restart to submit BIOs and return + * 0 or 1. + * The return value 0 means that it has become able to submit + * them now so that this ioband device will continue its work. + * The return value 1 means that it is still unable to submit + * them so that this device will stop its work. And this + * policy module has to reactivate the device when it gets + * to be able to submit BIOs. + * g_hold_bio : To hold a given BIO until it is submitted. + * The default function is used when this method is undefined. + * g_pop_bio : To select and get the best BIO to submit. + * g_group_ctr : To initalize the policy own members of struct ioband_group. + * g_group_dtr : Called when struct ioband_group is removed. + * g_set_param : To update the policy own date. + * The parameters can be passed through "dmsetup message" + * command. + * g_should_block : Called every time this ioband device receive a BIO. + * Return 1 if a given group can't receive any more BIOs, + * otherwise return 0. + * g_show : Show the configuration. + */ + +int policy_range_bw_init(struct ioband_device *dp, int argc, char **argv) +{ + long val; + int r = 0; + + if (argc < 1) + val = 0; + else { + r = strict_strtol(argv[0], 0, &val); + if (r || val < 0) + return -EINVAL; + } + + dp->g_can_submit = has_right_to_issue; + dp->g_prepare_bio = range_bw_prepare_token; + dp->g_restart_bios = range_bw_restart_bios; + dp->g_group_ctr = policy_range_bw_ctr; + dp->g_group_dtr = policy_range_bw_dtr; + dp->g_set_param = policy_range_bw_param; + dp->g_should_block = range_bw_queue_full; + dp->g_show = policy_range_bw_show; + + dp->g_min_bw_total = 0; + dp->g_running_gp = NULL; + dp->g_total_min_bw_token = 0; + dp->g_io_mode = MINBW_IO_MODE; + dp->g_consumed_min_bw_token = 0; + dp->g_current = NULL; + dp->g_next_time_period = 0; + dp->g_time_period_expired = TIME_SLICE_NOT_EXPIRED; + + dp->g_token_unit = PAGE_SHIFT - 9; + init_range_bw_token_bucket(dp, val); + + return 0; +} Index: linux-2.6.31/Documentation/device-mapper/range-bw.txt =================================================================== --- /dev/null +++ linux-2.6.31/Documentation/device-mapper/range-bw.txt @@ -0,0 +1,99 @@ +Range-BW I/O controller by Dong-Jae Kang <djk@etri.re.kr> + + +1. Introduction +=============== + +The design of Range-BW is related with three another parts, Cgroup, +bio-cgroup (or blkio-cgroup) and dm-ioband and it was implemented as +an additional controller for dm-ioband. +Cgroup framework is used to support process grouping mechanism and +bio-cgroup is used to control delayed I/O or non-direct I/O. Finally, +dm-ioband is a kind of I/O controller allowing the proportional I/O +bandwidth to process groups based on its priority. +The supposed controller supports the process group-based range +bandwidth according to the priority or importance of the group. Range +bandwidth means the predicable I/O bandwidth with minimum and maximum +value defined by administrator. + +Minimum I/O bandwidth should be guaranteed for stable performance or +reliability of specific service and I/O bandwidth over maximum should +be throttled to protect the limited I/O resource from +over-provisioning in unnecessary usage or to reserve the I/O bandwidth +for another use. +So, Range-BW was implemented to include the two concepts, guaranteeing +of minimum I/O requirement and limitation of unnecessary bandwidth +depending on its priority. +And it was implemented as device mapper driver such like dm-ioband. +So, it is independent of the underlying specific I/O scheduler, for +example, CFQ, AS, NOOP, deadline and so on. + +* Attention +Range-BW supports the predicable I/O bandwidth, but it should be +configured in the scope of total I/O bandwidth of the I/O system to +guarantee the minimum I/O requirement. For example, if total I/O +bandwidth is 40Mbytes/sec, + +the summary of I/O bandwidth configured in each process group should +be equal or smaller than 40Mbytes/sec. +So, we need to check total I/O bandwidth before set it up. + +2. Setup and Installation +========================= + +This part is same with dm-ioband, +../../Documentation/device-mapper/ioband.txt or +http://sourceforge.net/apps/trac/ioband/wiki/dm-ioband/man/setup +except the allocation of range-bw values. + +3. Usage +======== + +It is very useful to refer the documentation for dm-ioband in +../../Documentation/device-mapper/ioband.txt or + +http://sourceforge.net/apps/trac/ioband/wiki/dm-ioband, because +Range-BW follows the basic semantics of dm-ioband. +This example is for range-bw configuration. + +# mount the cgroup +mount -t cgroup -o blkio none /root/cgroup/blkio + +# create the process groups (3 groups) +mkdir /root/cgroup/blkio/bgroup1 +mkdir /root/cgroup/blkio/bgroup2 +mkdir /root/cgroup/blkio/bgroup3 + +# create the ioband device ( name : ioband1 ) +echo "0 $(blockdev --getsize /dev/sdb2) ioband /dev/sdb2 1 0 0 none +range-bw 0 :0:0" | dmsetup create ioband1 +: Attention - device name (/dev/sdb2) should be modified depending on +your system + +# init ioband device ( type and policy ) +dmsetup message ioband1 0 type cgroup +dmsetup message ioband1 0 policy range-bw + +# attach the groups to the ioband device +dmsetup message ioband1 0 attach 2 +dmsetup message ioband1 0 attach 3 +dmsetup message ioband1 0 attach 4 +: group number can be referred in /root/cgroup/blkio/bgroup1/blkio.id + +# allocate the values ( range-bw ) : XXX Kbytes +: the sum of minimum I/O bandwidth in each group should be equal or +smaller than total bandwidth to be supported by your system + +# range : about 100~500 Kbytes +dmsetup message ioband1 0 range-bw 2:100:500 + +# range : about 700~1000 Kbytes +dmsetup message ioband1 0 range-bw 3:700:1000 + +# range : about 30~35Mbytes +dmsetup message ioband1 0 range-bw 4:30000:35000 + +You can confirm the configuration of range-bw by using this command : +[root@localhost range-bw]# dmsetup table --target ioband +ioband1: 0 305235000 ioband 8:18 1 4 128 cgroup \ + range-bw 16384 :0:0 2:100:500 3:700:1000 4:30000:35000 Index: linux-2.6.31/include/trace/events/dm-ioband.h =================================================================== --- /dev/null +++ linux-2.6.31/include/trace/events/dm-ioband.h @@ -0,0 +1,242 @@ +#if !defined(_TRACE_DM_IOBAND_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_DM_IOBAND_H + +#include <linux/tracepoint.h> + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM dm-ioband + +TRACE_EVENT(ioband_hold_urgent_bio, + + TP_PROTO(struct ioband_group *gp, struct bio *bio), + + TP_ARGS(gp, bio), + + TP_STRUCT__entry( + __string( g_name, gp->c_banddev->g_name ) + __field( int, c_id ) + __field( int, g_blocked ) + __field( int, c_blocked ) + __field( dev_t, dev ) + __field( sector_t, sector ) + __field( unsigned int, nr_sector ) + __field( char, rw ) + ), + + TP_fast_assign( + __assign_str(g_name, gp->c_banddev->g_name); + __entry->c_id = gp->c_id; + __entry->g_blocked = gp->c_banddev->g_blocked; + __entry->c_blocked = gp->c_blocked; + __entry->dev = bio->bi_bdev->bd_dev; + __entry->sector = bio->bi_sector; + __entry->nr_sector = bio->bi_size >> 9; + __entry->rw = (bio_data_dir(bio) == READ) ? 'R' : 'W'; + ), + + TP_printk("%s,%d: %d,%d %c %llu + %u %d %d", + __get_str(g_name), __entry->c_id, + MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rw, + (unsigned long long)__entry->sector, + __entry->nr_sector, __entry->g_blocked, __entry->c_blocked) +); + +TRACE_EVENT(ioband_hold_bio, + + TP_PROTO(struct ioband_group *gp, struct bio *bio), + + TP_ARGS(gp, bio), + + TP_STRUCT__entry( + __string( g_name, gp->c_banddev->g_name ) + __field( int, c_id ) + __field( int, g_blocked ) + __field( int, c_blocked ) + __field( dev_t, dev ) + __field( sector_t, sector ) + __field( unsigned int, nr_sector ) + __field( char, rw ) + ), + + TP_fast_assign( + __assign_str(g_name, gp->c_banddev->g_name); + __entry->c_id = gp->c_id; + __entry->g_blocked = gp->c_banddev->g_blocked; + __entry->c_blocked = gp->c_blocked; + __entry->dev = bio->bi_bdev->bd_dev; + __entry->sector = bio->bi_sector; + __entry->nr_sector = bio->bi_size >> 9; + __entry->rw = (bio_data_dir(bio) == READ) ? 'R' : 'W'; + ), + + TP_printk("%s,%d: %d,%d %c %llu + %u %d %d", + __get_str(g_name), __entry->c_id, + MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rw, + (unsigned long long)__entry->sector, + __entry->nr_sector, __entry->g_blocked, __entry->c_blocked) +); + +TRACE_EVENT(ioband_make_pback_list, + + TP_PROTO(struct ioband_group *gp, struct bio *bio), + + TP_ARGS(gp, bio), + + TP_STRUCT__entry( + __string( g_name, gp->c_banddev->g_name ) + __field( int, c_id ) + __field( int, g_blocked ) + __field( int, c_blocked ) + __field( dev_t, dev ) + __field( sector_t, sector ) + __field( unsigned int, nr_sector ) + __field( char, rw ) + ), + + TP_fast_assign( + __assign_str(g_name, gp->c_banddev->g_name); + __entry->c_id = gp->c_id; + __entry->g_blocked = gp->c_banddev->g_blocked; + __entry->c_blocked = gp->c_blocked; + __entry->dev = bio->bi_bdev->bd_dev; + __entry->sector = bio->bi_sector; + __entry->nr_sector = bio->bi_size >> 9; + __entry->rw = (bio_data_dir(bio) == READ) ? 'R' : 'W'; + ), + + TP_printk("%s,%d: %d,%d %c %llu + %u %d %d", + __get_str(g_name), __entry->c_id, + MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rw, + (unsigned long long)__entry->sector, + __entry->nr_sector, __entry->g_blocked, __entry->c_blocked) +); + +TRACE_EVENT(ioband_make_issue_list, + + TP_PROTO(struct ioband_group *gp, struct bio *bio), + + TP_ARGS(gp, bio), + + TP_STRUCT__entry( + __string( g_name, gp->c_banddev->g_name ) + __field( int, c_id ) + __field( int, g_blocked ) + __field( int, c_blocked ) + __field( dev_t, dev ) + __field( sector_t, sector ) + __field( unsigned int, nr_sector ) + __field( char, rw ) + ), + + TP_fast_assign( + __assign_str(g_name, gp->c_banddev->g_name); + __entry->c_id = gp->c_id; + __entry->g_blocked = gp->c_banddev->g_blocked; + __entry->c_blocked = gp->c_blocked; + __entry->dev = bio->bi_bdev->bd_dev; + __entry->sector = bio->bi_sector; + __entry->nr_sector = bio->bi_size >> 9; + __entry->rw = (bio_data_dir(bio) == READ) ? 'R' : 'W'; + ), + + TP_printk("%s,%d: %d,%d %c %llu + %u %d %d", + __get_str(g_name), __entry->c_id, + MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rw, + (unsigned long long)__entry->sector, + __entry->nr_sector, __entry->g_blocked, __entry->c_blocked) +); + +TRACE_EVENT(ioband_release_urgent_bios, + + TP_PROTO(struct ioband_device *dp, struct bio *bio), + + TP_ARGS(dp, bio), + + TP_STRUCT__entry( + __string( g_name, dp->g_name ) + __field( int, g_blocked ) + __field( dev_t, dev ) + __field( sector_t, sector ) + __field( unsigned int, nr_sector ) + __field( char, rw ) + ), + + TP_fast_assign( + __assign_str(g_name, dp->g_name); + __entry->g_blocked = dp->g_blocked; + __entry->dev = bio->bi_bdev->bd_dev; + __entry->sector = bio->bi_sector; + __entry->nr_sector = bio->bi_size >> 9; + __entry->rw = (bio_data_dir(bio) == READ) ? 'R' : 'W'; + ), + + TP_printk("%s: %d,%d %c %llu + %u %d", + __get_str(g_name), + MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rw, + (unsigned long long)__entry->sector, + __entry->nr_sector, __entry->g_blocked) +); + +TRACE_EVENT(ioband_make_request, + + TP_PROTO(struct ioband_device *dp, struct bio *bio), + + TP_ARGS(dp, bio), + + TP_STRUCT__entry( + __string( g_name, dp->g_name ) + __field( int, c_id ) + __field( dev_t, dev ) + __field( sector_t, sector ) + __field( unsigned int, nr_sector ) + __field( char, rw ) + ), + + TP_fast_assign( + __assign_str(g_name, dp->g_name); + __entry->dev = bio->bi_bdev->bd_dev; + __entry->sector = bio->bi_sector; + __entry->nr_sector = bio->bi_size >> 9; + __entry->rw = (bio_data_dir(bio) == READ) ? 'R' : 'W'; + ), + + TP_printk("%s: %d,%d %c %llu + %u", + __get_str(g_name), + MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rw, + (unsigned long long)__entry->sector, + __entry->nr_sector) +); + +TRACE_EVENT(ioband_pushback_bio, + + TP_PROTO(struct ioband_device *dp, struct bio *bio), + + TP_ARGS(dp, bio), + + TP_STRUCT__entry( + __string( g_name, dp->g_name ) + __field( dev_t, dev ) + __field( sector_t, sector ) + __field( unsigned int, nr_sector ) + __field( char, rw ) + ), + + TP_fast_assign( + __assign_str(g_name, dp->g_name); + __entry->dev = bio->bi_bdev->bd_dev; + __entry->sector = bio->bi_sector; + __entry->nr_sector = bio->bi_size >> 9; + __entry->rw = (bio_data_dir(bio) == READ) ? 'R' : 'W'; + ), + + TP_printk("%s: %d,%d %c %llu + %u", + __get_str(g_name), + MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rw, + (unsigned long long)__entry->sector, + __entry->nr_sector) +); + +#endif /* _TRACE_DM_IOBAND_H */ + +/* This part must be outside protection */ +#include <trace/define_trace.h>