Messages in this thread Patch in this message | | | Date | Sun, 28 Feb 2010 08:59:01 GMT | From | "tip-bot for Paul E. McKenney" <> | Subject | [tip:core/rcu] rcu: Fix holdoff for accelerated GPs for last non-dynticked CPU |
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Commit-ID: 622ea685f1fafdf84d612440535c84341f0860b8 Gitweb: http://git.kernel.org/tip/622ea685f1fafdf84d612440535c84341f0860b8 Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com> AuthorDate: Sat, 27 Feb 2010 14:53:07 -0800 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Sun, 28 Feb 2010 09:17:42 +0100
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> --- kernel/rcutree_plugin.h | 8 +++++--- 1 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 464ad2c..79b53bd 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; }
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