From c7af77b584b02d3e321b00203a618a9c93782121 Mon Sep 17 00:00:00 2001 From: Livio Soares Date: Tue, 18 Dec 2007 15:21:13 +0100 Subject: 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 Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/rwsem.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/rwsem.c b/kernel/rwsem.c index 1ec620c0306..cae050b05f5 100644 --- a/kernel/rwsem.c +++ b/kernel/rwsem.c @@ -6,6 +6,7 @@ #include #include +#include #include #include @@ -15,7 +16,7 @@ /* * lock for reading */ -void down_read(struct rw_semaphore *sem) +void __sched down_read(struct rw_semaphore *sem) { might_sleep(); rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_); @@ -42,7 +43,7 @@ EXPORT_SYMBOL(down_read_trylock); /* * lock for writing */ -void down_write(struct rw_semaphore *sem) +void __sched down_write(struct rw_semaphore *sem) { might_sleep(); rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_); -- cgit v1.2.3