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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2012-01-04 11:44:57 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-02-21 09:03:22 -0800 |
| commit | 18fec7d8758dd416904da205375e6fa667defc80 (patch) | |
| tree | 768f505120e075d9f93b83d0657dcaf712ea18e0 | |
| parent | 4c62abc90bea439a4b50aad9f67a310fb9c392e1 (diff) | |
| download | op-kernel-dev-18fec7d8758dd416904da205375e6fa667defc80.zip op-kernel-dev-18fec7d8758dd416904da205375e6fa667defc80.tar.gz | |
rcu: Improve synchronize_rcu() diagnostics
Although TREE_PREEMPT_RCU indirectly uses might_sleep() to detect illegal
use of synchronize_sched() and synchronize_rcu_bh() from within an RCU
read-side critical section, this might_sleep() check is bypassed when
there is only a single CPU (for example, when running an SMP kernel on
a single-CPU system). This patch therefore adds a might_sleep() call
to the rcu_blocking_is_gp() check that is unconditionally invoked from
both synchronize_sched() and synchronize_rcu_bh().
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| -rw-r--r-- | include/linux/rcutree.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 6745846..73e7195 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -83,6 +83,7 @@ extern void rcu_sched_force_quiescent_state(void); /* A context switch is a grace period for RCU-sched and RCU-bh. */ static inline int rcu_blocking_is_gp(void) { + might_sleep(); /* Check for RCU read-side critical section. */ return num_online_cpus() == 1; } |
