Commit 622ea685 authored Feb 27, 2010 by Paul E. McKenney Committed by Ingo Molnar Feb 28, 2010

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>

parent 71da8132

kernel/rcutree_plugin.h

+5 −3

Original line number	Diff line number	Diff line
		@@ -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;
		}