rcu: Make RCU lockdep check the lockdep_recursion variable
authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Thu, 15 Apr 2010 19:50:39 +0000 (12:50 -0700)
committerIngo Molnar <mingo@elte.hu>
Mon, 19 Apr 2010 06:37:19 +0000 (08:37 +0200)
commitbc293d62b26ec590afc90a9e0a31c45d355b7bd8
tree4b61dee53e849f0ba1d5a7fef58522e224be836e
parent50aec0024eccb1d5f540ab64a1958eebcdb9340c
rcu: Make RCU lockdep check the lockdep_recursion variable

The lockdep facility temporarily disables lockdep checking by
incrementing the current->lockdep_recursion variable.  Such
disabling happens in NMIs and in other situations where lockdep
might expect to recurse on itself.

This patch therefore checks current->lockdep_recursion, disabling RCU
lockdep splats when this variable is non-zero.  In addition, this patch
removes the "likely()", as suggested by Lai Jiangshan.

Reported-by: Frederic Weisbecker <fweisbec@gmail.com>
Reported-by: David Miller <davem@davemloft.net>
Tested-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
Cc: eric.dumazet@gmail.com
LKML-Reference: <20100415195039.GA22623@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
include/linux/rcupdate.h
kernel/rcupdate.c