]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
workqueue: debug flushing deadlocks with lockdep
authorJohannes Berg <johannes@sipsolutions.net>
Fri, 19 Oct 2007 06:39:55 +0000 (23:39 -0700)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Fri, 19 Oct 2007 18:53:38 +0000 (11:53 -0700)
commit4e6045f134784f4b158b3c0f7a282b04bd816887
tree3304628f666c8524accd10f40da48cfba8b08608
parentcf7b708c8d1d7a27736771bcf4c457b332b0f818
workqueue: debug flushing deadlocks with lockdep

In the following scenario:

code path 1:
  my_function() -> lock(L1); ...; flush_workqueue(); ...

code path 2:
  run_workqueue() -> my_work() -> ...; lock(L1); ...

you can get a deadlock when my_work() is queued or running
but my_function() has acquired L1 already.

This patch adds a pseudo-lock to each workqueue to make lockdep
warn about this scenario.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/lockdep.h
include/linux/workqueue.h
kernel/lockdep.c
kernel/workqueue.c