27 messages in org.freebsd.freebsd-hackersRe: How does swap work address spacew...| From | Sent On | Attachments |
|---|---|---|
| Daniel Lang | Jul 5, 2002 4:35 am | |
| David Schultz | Jul 5, 2002 6:34 am | |
| David Schultz | Jul 5, 2002 6:38 am | |
| Terry Lambert | Jul 5, 2002 7:33 am | |
| Daniel Lang | Jul 5, 2002 4:41 pm | |
| Darren Pilgrim | Jul 5, 2002 5:57 pm | |
| Bernd Walter | Jul 5, 2002 7:06 pm | |
| Terry Lambert | Jul 5, 2002 11:12 pm | |
| Matthew Dillon | Jul 6, 2002 1:10 am | |
| Darren Pilgrim | Jul 6, 2002 2:36 pm | |
| Matthew D. Fuller | Jul 6, 2002 2:51 pm | |
| Bernd Walter | Jul 6, 2002 3:06 pm | |
| Darren Pilgrim | Jul 6, 2002 3:42 pm | |
| Terry Lambert | Jul 6, 2002 4:00 pm | |
| Bernd Walter | Jul 6, 2002 4:04 pm | |
| Bernd Walter | Jul 6, 2002 4:13 pm | |
| Matthew Dillon | Jul 6, 2002 4:33 pm | |
| Matthew Dillon | Jul 6, 2002 4:42 pm | |
| Bernd Walter | Jul 6, 2002 5:09 pm | |
| Matthew Dillon | Jul 6, 2002 5:33 pm | |
| Bernd Walter | Jul 6, 2002 5:42 pm | |
| Matthew Dillon | Jul 6, 2002 5:46 pm | |
| Ian Dowse | Jul 6, 2002 5:49 pm | |
| Bernd Walter | Jul 6, 2002 6:21 pm | |
| Darren Pilgrim | Jul 6, 2002 10:01 pm | |
| Matthew Dillon | Jul 6, 2002 10:09 pm | |
| Darren Pilgrim | Jul 6, 2002 10:43 pm |
| Subject: | Re: How does swap work address spacewise? | |
|---|---|---|
| From: | Bernd Walter (tic...@cicely5.cicely.de) | |
| Date: | Jul 6, 2002 3:06:58 pm | |
| List: | org.freebsd.freebsd-hackers | |
On Sat, Jul 06, 2002 at 02:37:02PM -0700, Darren Pilgrim wrote:
Bernd Walter wrote:
On Fri, Jul 05, 2002 at 05:58:15PM -0700, Darren Pilgrim wrote:
If RAM + swap can be more than 4GB, how does FreeBSD address swap on a 32-bit machine? Does the kernel internally use a wider address space
The same way it does on every partitition: using block numbers. That way you can address 1TByte.
I thought the limit for filesystems was 2TB?
The Blocknumber is signed that gives: 2^31 * 512Bytes
And you can have more than a single swap partition.
Up to four, so then the theoretical limit for swap is 8TB?
4 is just a default. [61]cicely9# swapinfo Device 1K-blocks Used Avail Capacity Type /dev/da1b 105472 80 105392 0% Interleaved /dev/da11b 174880 0 174880 0% Interleaved /dev/da4b 211456 0 211456 0% Interleaved /dev/da5b 211456 0 211456 0% Interleaved /dev/da6b 211456 0 211456 0% Interleaved /dev/da7b 211456 0 211456 0% Interleaved /dev/da8b 211456 0 211456 0% Interleaved /dev/da9b 211456 0 211456 0% Interleaved /dev/da10b 211456 0 211456 0% Interleaved Total 1760544 80 1760464 0%
The limit here is the maximum number of harddisks, which is IIRC 512 per driver. This cames from the available minor bits in the device node.
In reality managementstructures which have to be in kernel addressspace is limiting swap before.
Do these management structures grow as swap grows, or do they only change as the utilization increases?
AFAIK there is a static part. Possible not memory but only KVM addressspace. Also AFAIK it makes a difference if you allocate the same space using a single partition or in more than one.
-- B.Walter COSMO-Project http://www.cosmo-project.de tic...@cicely.de Usergroup in...@cosmo-project.de
To Unsubscribe: send mail to majo...@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message