atom feed10 messages in org.freebsd.freebsd-netduplicate read/write locks in net/pf...
FromSent OnAttachments
Luigi RizzoAug 17, 2005 12:05 am 
Max LaierAug 17, 2005 2:35 am 
Julian ElischerAug 17, 2005 3:20 am 
Luigi RizzoAug 18, 2005 12:02 am 
Max LaierAug 18, 2005 1:32 am 
Luigi RizzoAug 18, 2005 7:57 am 
Luigi RizzoAug 18, 2005 2:31 pm 
John BaldwinAug 18, 2005 4:28 pm 
Stephan UphoffAug 20, 2005 10:39 pm 
Stephan UphoffAug 20, 2005 11:02 pm 
Subject:duplicate read/write locks in net/pfil.c and netinet/ip_fw2.c
From:Luigi Rizzo (riz@icir.org)
Date:Aug 18, 2005 2:31:05 pm
List:org.freebsd.freebsd-net

On Thu, Aug 18, 2005 at 10:18:33AM -0400, Stephan Uphoff wrote:

On Thu, 2005-08-18 at 03:57, Luigi Rizzo wrote:

...

In fact i don't understand why you consider spinning and sleeping on a mutex two different things.

The major difference between sleeping (cv_wait,msleep,..) and blocking on a mutex is priority inheritance. If you need to be able to use (non-spin) mutexes while holding a [R|W]LOCK and use a [R|W]LOCK while holding a (non-spin) mutex then you need to implement priority inheritance for [R|W]LOCKs.

is that required (in FreeBSD, i mean) for algorithmic correctness or just for performance ?

cheers luigi