Commit 554cecaf authored Mar 07, 2012 by Diwakar Tundlam Committed by Ingo Molnar Mar 12, 2012

sched/nohz: Correctly initialize 'next_balance' in 'nohz' idle balancer



The 'next_balance' field of 'nohz' idle balancer must be initialized
to jiffies. Since jiffies is initialized to negative 300 seconds the
'nohz' idle balancer does not run for the first 300s (5mins) after
bootup. If no new processes are spawed or no idle cycles happen, the
load on the cpus will remain unbalanced for that duration.

Signed-off-by: Diwakar Tundlam <dtundlam@nvidia.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1DD7BFEDD3147247B1355BEFEFE4665237994F30EF@HQMAIL04.nvidia.com


Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 5fbd036b

kernel/sched/fair.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -5571,6 +5571,7 @@ __init void init_sched_fair_class(void)
		open_softirq(SCHED_SOFTIRQ, run_rebalance_domains);

		#ifdef CONFIG_NO_HZ
		nohz.next_balance = jiffies;
		zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT);
		cpu_notifier(sched_ilb_notifier, 0);
		#endif

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