hung_task: fix false positive during vfork
authorMandeep Singh Baines <msb@chromium.org>
Tue, 3 Jan 2012 22:41:13 +0000 (14:41 -0800)
committerRohan Somvanshi <rsomvanshi@nvidia.com>
Wed, 11 Jan 2012 18:34:32 +0000 (10:34 -0800)
commitdde30940487f409c960ac80804ac5b76b433d252
treeb42e5818ef9205fffc6b814ca808933afe6f6471
parent3bb1d780e875ecceb7e0c384dc64bb3b8914e1c4
hung_task: fix false positive during vfork

commit f9fab10bbd768b0e5254e53a4a8477a94bfc4b96 upstream.

vfork parent uninterruptibly and unkillably waits for its child to
exec/exit. This wait is of unbounded length. Ignore such waits
in the hung_task detector.

Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Reported-by: Sasha Levin <levinsasha928@gmail.com>
LKML-Reference: <1325344394.28904.43.camel@lappy>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Kacur <jkacur@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Change-Id: I12ed227da1fb7099978c73b65a756caf51a95553
Reviewed-on: http://git-master/r/74230
Reviewed-by: Varun Wadekar <vwadekar@nvidia.com>
Tested-by: Varun Wadekar <vwadekar@nvidia.com>
kernel/hung_task.c