]> git.karo-electronics.de Git - karo-tx-linux.git/commit
printk: Release console_sem after logbuf_lock
authorPeter Zijlstra <a.p.zijlstra@chello.nl>
Tue, 7 Jun 2011 09:15:33 +0000 (11:15 +0200)
committerIngo Molnar <mingo@elte.hu>
Tue, 7 Jun 2011 10:50:02 +0000 (12:50 +0200)
commit0b5e1c5255e7ee8670e077e8224e5c2281229a5b
treeeb6f967b14d69553e380ab2f13a2dcd8789e865e
parent59c5f46fbe01a00eedf54a23789634438bb80603
printk: Release console_sem after logbuf_lock

Release console_sem after unlocking the logbuf_lock so that we don't
generate wakeups while holding logbuf_lock. This avoids some lock
inversion troubles once we remove the lockdep_off bits between
logbuf_lock and rq->lock (prints while holding rq->lock vs doing
wakeups while holding logbuf_lock).

There's of course still an actual deadlock where the printk()s under
rq->lock will issue a wakeup from the up() call, but lockdep won't
warn about that since semaphores are not tracked.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-j8swthl12u73h4znbvitljzd@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
kernel/printk.c