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| author | Lai Jiangshan <laijs@cn.fujitsu.com> | 2010-03-18 12:25:33 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-03-18 21:25:32 +0100 |
| commit | 0cff810f54b3b52075c27f7a7021d5b195264b6c (patch) | |
| tree | 671189b10e1ac4d12a26d9a337a2ca053faed107 /include/linux/rcupdate.h | |
| parent | 7f5b774275df8c76a959eae7488128b637fcbfc8 (diff) | |
| download | lwn-0cff810f54b3b52075c27f7a7021d5b195264b6c.tar.gz lwn-0cff810f54b3b52075c27f7a7021d5b195264b6c.zip | |
rcu: Fix local_irq_disable() CONFIG_PROVE_RCU=y false positives
It is documented that local_irq_disable() also delimits RCU_SCHED
read-site critical sections.
See the document of synchronize_sched() or
Documentation/RCU/whatisRCU.txt.
So we have to test irqs_disabled() in rcu_read_lock_sched_held().
Otherwise rcu-lockdep brings incorrect complaint.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.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: <1268940334-10892-1-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/rcupdate.h')
| -rw-r--r-- | include/linux/rcupdate.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index e1bdc4bfd275..872a98e13d6a 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -149,7 +149,7 @@ static inline int rcu_read_lock_sched_held(void) return 1; if (debug_locks) lockdep_opinion = lock_is_held(&rcu_sched_lock_map); - return lockdep_opinion || preempt_count() != 0; + return lockdep_opinion || preempt_count() != 0 || irqs_disabled(); } #else /* #ifdef CONFIG_PREEMPT */ static inline int rcu_read_lock_sched_held(void) @@ -180,7 +180,7 @@ static inline int rcu_read_lock_bh_held(void) #ifdef CONFIG_PREEMPT static inline int rcu_read_lock_sched_held(void) { - return !rcu_scheduler_active || preempt_count() != 0; + return !rcu_scheduler_active || preempt_count() != 0 || irqs_disabled(); } #else /* #ifdef CONFIG_PREEMPT */ static inline int rcu_read_lock_sched_held(void) |