| From | "Paul E. McKenney" <> | Subject | [PATCH RFC tip/core/rcu 02/41] rcu: Improve synchronize_rcu() diagnostics | Date | Wed, 1 Feb 2012 11:41:20 -0800 |
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From: Frederic Weisbecker <fweisbec@gmail.com>
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> --- 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; } -- 1.7.8
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