From 040a0a37100563754bb1fee6ff6427420bcfa609 Mon Sep 17 00:00:00 2001 From: Maarten Lankhorst Date: Mon, 24 Jun 2013 10:30:04 +0200 Subject: mutex: Add support for wound/wait style locks Wound/wait mutexes are used when other multiple lock acquisitions of a similar type can be done in an arbitrary order. The deadlock handling used here is called wait/wound in the RDBMS literature: The older tasks waits until it can acquire the contended lock. The younger tasks needs to back off and drop all the locks it is currently holding, i.e. the younger task is wounded. For full documentation please read Documentation/ww-mutex-design.txt. References: https://lwn.net/Articles/548909/ Signed-off-by: Maarten Lankhorst Acked-by: Daniel Vetter Acked-by: Rob Clark Acked-by: Peter Zijlstra Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Cc: rostedt@goodmis.org Cc: daniel@ffwll.ch Cc: Linus Torvalds Cc: Andrew Morton Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/51C8038C.9000106@canonical.com Signed-off-by: Ingo Molnar --- lib/debug_locks.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'lib/debug_locks.c') diff --git a/lib/debug_locks.c b/lib/debug_locks.c index f2fa60c59343..96c4c633d95e 100644 --- a/lib/debug_locks.c +++ b/lib/debug_locks.c @@ -30,6 +30,7 @@ EXPORT_SYMBOL_GPL(debug_locks); * a locking bug is detected. */ int debug_locks_silent; +EXPORT_SYMBOL_GPL(debug_locks_silent); /* * Generic 'turn off all lock debugging' function: @@ -44,3 +45,4 @@ int debug_locks_off(void) } return 0; } +EXPORT_SYMBOL_GPL(debug_locks_off); -- cgit v1.2.3