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| author |   Frederic Weisbecker <fweisbec@gmail.com> | 2009-12-16 20:21:05 +0100 |
|---|---|---|
| committer |   Ingo Molnar <mingo@elte.hu> | 2009-12-17 09:46:44 +0100 |
| commit | 234da7bcdc7aaa935846534c3b726dbc79a9cdd5 (patch) | |
| tree | a391afd465d6493a9f1bb274c225bab4d303aad0 /include/linux/rcutiny.h | |
| parent | sched: Make warning less noisy (diff) | |
| download | linux-dev-234da7bcdc7aaa935846534c3b726dbc79a9cdd5.tar.xz linux-dev-234da7bcdc7aaa935846534c3b726dbc79a9cdd5.zip | |
sched: Teach might_sleep() about preemptible RCU
In practice, it is harmless to voluntarily sleep in a
rcu_read_lock() section if we are running under preempt rcu, but
it is illegal if we build a kernel running non-preemptable rcu.
Currently, might_sleep() doesn't notice sleepable operations
under rcu_read_lock() sections if we are running under
preemptable rcu because preempt_count() is left untouched after
rcu_read_lock() in this case. But we want developers who test
their changes under such config to notice the "sleeping while
atomic" issues.
So we add rcu_read_lock_nesting to prempt_count() in
might_sleep() checks.
[ v2: Handle rcu-tiny ]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <1260991265-8451-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/rcutiny.h')
| -rw-r--r-- | include/linux/rcutiny.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index c4ba9a78721e..96cc307ed9f4 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -101,4 +101,9 @@ static inline void exit_rcu(void) { } +static inline int rcu_preempt_depth(void) +{ + return 0; +} + #endif /* __LINUX_RCUTINY_H */ |