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| author | Paul E. McKenney <paul.mckenney@linaro.org> | 2012-06-21 09:54:10 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-09-23 07:41:53 -0700 |
| commit | bfa00b4c4028f39357d16279ff0fddf550241593 (patch) | |
| tree | 81f7ba2a050d2ddb033bf690ade41052a866d7fb /kernel/rcutree.c | |
| parent | 7fdefc10e1d730d4608cc59d386bc446f5b9ee99 (diff) | |
| download | linux-bfa00b4c4028f39357d16279ff0fddf550241593.tar.gz linux-bfa00b4c4028f39357d16279ff0fddf550241593.tar.xz | |
rcu: Prevent offline CPUs from executing RCU core code
Earlier versions of RCU invoked the RCU core from the CPU_DYING notifier
in order to note a quiescent state for the outgoing CPU. Because the
CPU is marked "offline" during the execution of the CPU_DYING notifiers,
the RCU core had to tolerate being invoked from an offline CPU. However,
commit b1420f1c (Make rcu_barrier() less disruptive) left only tracing
code in the CPU_DYING notifier, so the RCU core need no longer execute
on offline CPUs. This commit therefore enforces this restriction.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'kernel/rcutree.c')
| -rw-r--r-- | kernel/rcutree.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index f0c0c1b4b6d4..340a5f54b6af 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1892,6 +1892,8 @@ static void rcu_process_callbacks(struct softirq_action *unused) { struct rcu_state *rsp; + if (cpu_is_offline(smp_processor_id())) + return; trace_rcu_utilization("Start RCU core"); for_each_rcu_flavor(rsp) __rcu_process_callbacks(rsp); |