rcu: Inform the user about extended quiescent state on PROVE_RCU warning
authorFrederic Weisbecker <fweisbec@gmail.com>
Fri, 7 Oct 2011 16:22:01 +0000 (18:22 +0200)
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Sun, 11 Dec 2011 18:31:30 +0000 (10:31 -0800)
commit0464e937485f15d2add78e3b0f498469f4e6600d
tree4007c0643436591850ac8bc87e03601afb8f1920
parente6b80a3b0994ea6c3d876d72464f2debbfcfeb05
rcu: Inform the user about extended quiescent state on PROVE_RCU warning

Inform the user if an RCU usage error is detected by lockdep while in
an extended quiescent state (in this case, the RCU-free window in idle).
This is accomplished by adding a line to the RCU lockdep splat indicating
whether or not the splat occurred in extended quiescent state.

Uses of RCU from within extended quiescent state mode are totally ignored
by RCU, hence the importance of this diagnostic.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
kernel/lockdep.c