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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2010-02-27 14:53:07 -0800
committerIngo Molnar <mingo@elte.hu>2010-02-28 09:17:42 +0100
commit622ea685f1fafdf84d612440535c84341f0860b8 (patch)
tree68363e9a5a408ac78488c8c19e918fb6b17b76a7 /kernel
parent71da81324c83ef65bb196c7f874ac1c6996d8287 (diff)
downloadlinux-0-day-622ea685f1fafdf84d612440535c84341f0860b8.tar.gz
linux-0-day-622ea685f1fafdf84d612440535c84341f0860b8.tar.xz
rcu: Fix holdoff for accelerated GPs for last non-dynticked CPU
Make the holdoff only happen when the full number of attempts have been made. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1267311188-16603-1-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/rcutree_plugin.h8
1 files changed, 5 insertions, 3 deletions
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 464ad2cdee00a..79b53bda89432 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -1010,6 +1010,10 @@ int rcu_needs_cpu(int cpu)
int c = 0;
int thatcpu;
+ /* Check for being in the holdoff period. */
+ if (per_cpu(rcu_dyntick_holdoff, cpu) == jiffies)
+ return rcu_needs_cpu_quick_check(cpu);
+
/* Don't bother unless we are the last non-dyntick-idle CPU. */
for_each_cpu_not(thatcpu, nohz_cpu_mask)
if (thatcpu != cpu) {
@@ -1041,10 +1045,8 @@ int rcu_needs_cpu(int cpu)
}
/* If RCU callbacks are still pending, RCU still needs this CPU. */
- if (c) {
+ if (c)
raise_softirq(RCU_SOFTIRQ);
- per_cpu(rcu_dyntick_holdoff, cpu) = jiffies;
- }
return c;
}