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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-04-15 21:50:39 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-04-19 08:37:19 +0200 |
| commit | bc293d62b26ec590afc90a9e0a31c45d355b7bd8 (patch) | |
| tree | 4b61dee53e849f0ba1d5a7fef58522e224be836e /kernel | |
| parent | rcu: Update docs for rcu_access_pointer and rcu_dereference_protected (diff) | |
| download | linux-bc293d62b26ec590afc90a9e0a31c45d355b7bd8.tar.xz linux-bc293d62b26ec590afc90a9e0a31c45d355b7bd8.zip | |
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>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcupdate.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index 63fe25433980..03a7ea1579f6 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -69,6 +69,13 @@ EXPORT_SYMBOL_GPL(rcu_scheduler_active); #ifdef CONFIG_DEBUG_LOCK_ALLOC +int debug_lockdep_rcu_enabled(void) +{ + return rcu_scheduler_active && debug_locks && + current->lockdep_recursion == 0; +} +EXPORT_SYMBOL_GPL(debug_lockdep_rcu_enabled); + /** * rcu_read_lock_bh_held - might we be in RCU-bh read-side critical section? * |