]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
sched: mark rwsem functions as __sched for wchan/profiling
authorLivio Soares <livio@eecg.toronto.edu>
Tue, 18 Dec 2007 14:21:13 +0000 (15:21 +0100)
committerIngo Molnar <mingo@elte.hu>
Tue, 18 Dec 2007 14:21:13 +0000 (15:21 +0100)
commitc7af77b584b02d3e321b00203a618a9c93782121
treee7a8d5995e34065aa1bd610cb92684c5e5856119
parent051a1d1afa47206e23ae03f781c6795ce870e3d5
sched: mark rwsem functions as __sched for wchan/profiling

This following commit

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=fdf8cb0909b531f9ae8f9b9d7e4eb35ba3505f07

un-inlined a low-level rwsem function, but did not mark it as __sched.
The result is that it now shows up as thread wchan (which also affects
/proc/profile stats).  The following simple patch fixes this by properly
marking rwsem_down_failed_common() as a __sched function.

Also in this patch, which is up for discussion, marks down_read() and
down_write() proper as __sched.  For profiling, it is pretty much
useless to know that a semaphore is beig help - it is necessary to know
_which_ one.  By going up another frame on the stack, the information
becomes much more useful.

In summary, the below change to lib/rwsem.c should be applied; the
changes to kernel/rwsem.c could be applied if other kernel hackers agree
with my proposal that down_read()/down_write() in the profile is not
enough.

[ akpm@linux-foundation.org: build fix ]

Signed-off-by: Livio Soares <livio@eecg.toronto.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
kernel/rwsem.c
lib/rwsem.c