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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2011-08-20 18:29:32 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2011-09-28 21:38:48 -0700 |
| commit | e90c53d3e238dd0b7b02964370e8fece1778df96 (patch) | |
| tree | 23e5b8623c2c37bd8a4656c66266209872f80701 /kernel/rcutree.c | |
| parent | 5b61b0baa9e80289c53413e573befc5790a04ac7 (diff) | |
| download | op-kernel-dev-e90c53d3e238dd0b7b02964370e8fece1778df96.zip op-kernel-dev-e90c53d3e238dd0b7b02964370e8fece1778df96.tar.gz | |
rcu: Remove rcu_needs_cpu_flush() to avoid false quiescent states
The purpose of rcu_needs_cpu_flush() was to iterate on pushing the
current grace period in order to help the current CPU enter dyntick-idle
mode. However, this can result in failures if the CPU starts entering
dyntick-idle mode, but then backs out. In this case, the call to
rcu_pending() from rcu_needs_cpu_flush() might end up announcing a
non-existing quiescent state.
This commit therefore removes rcu_needs_cpu_flush() in favor of letting
the dyntick-idle machinery at the end of the softirq handler push the
loop along via its call to rcu_pending().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcutree.c')
| -rw-r--r-- | kernel/rcutree.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 8455043..e75df0c 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1528,9 +1528,6 @@ static void rcu_process_callbacks(struct softirq_action *unused) &__get_cpu_var(rcu_sched_data)); __rcu_process_callbacks(&rcu_bh_state, &__get_cpu_var(rcu_bh_data)); rcu_preempt_process_callbacks(); - - /* If we are last CPU on way to dyntick-idle mode, accelerate it. */ - rcu_needs_cpu_flush(); trace_rcu_utilization("End RCU core"); } |
