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| author | Lai Jiangshan <laijs@cn.fujitsu.com> | 2010-03-30 18:40:36 +0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-05-10 11:08:31 -0700 |
| commit | 5db356736acb9ba717df1aa9444e4e44cbb30a71 (patch) | |
| tree | 719d734fc3ef0f5fca3a7bf12a00dccfde278864 /kernel/rcutree_plugin.h | |
| parent | 0c34029abdfdea64420cb4264c4e91a776b22157 (diff) | |
| download | lwn-5db356736acb9ba717df1aa9444e4e44cbb30a71.tar.gz lwn-5db356736acb9ba717df1aa9444e4e44cbb30a71.zip | |
rcu: ignore offline CPUs in last non-dyntick-idle CPU check
Offline CPUs are not in nohz_cpu_mask, but can be ignored when checking
for the last non-dyntick-idle CPU. This patch therefore only checks
online CPUs for not being dyntick idle, allowing fast entry into
full-system dyntick-idle state even when there are some offline CPUs.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcutree_plugin.h')
| -rw-r--r-- | kernel/rcutree_plugin.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 79b53bda8943..687c4e90722e 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -1016,7 +1016,7 @@ int rcu_needs_cpu(int cpu) /* Don't bother unless we are the last non-dyntick-idle CPU. */ for_each_cpu_not(thatcpu, nohz_cpu_mask) - if (thatcpu != cpu) { + if (cpu_online(thatcpu) && thatcpu != cpu) { per_cpu(rcu_dyntick_drain, cpu) = 0; per_cpu(rcu_dyntick_holdoff, cpu) = jiffies - 1; return rcu_needs_cpu_quick_check(cpu); |