Messages in this thread Patch in this message | | | From | Vincent Guittot <> | Subject | [PATCH Resend 2/3] sched: fix init NOHZ_IDLE flag | Date | Mon, 3 Dec 2012 13:26:27 +0100 |
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On my smp platform which is made of 5 cores in 2 clusters,I have the nr_busy_cpus field of sched_group_power struct that is not null when the platform is fully idle. The root cause seems to be: During the boot sequence, some CPUs reach the idle loop and set their NOHZ_IDLE flag while waiting for others CPUs to boot. But the nr_busy_cpus field is initialized later with the assumption that all CPUs are in the busy state whereas some CPUs have already set their NOHZ_IDLE flag. We clear the NOHZ_IDLE flag when nr_busy_cpus is initialized in order to have a coherent configuration.
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> --- kernel/sched/core.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index bae620a..77a01c8 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5875,6 +5875,7 @@ static void init_sched_groups_power(int cpu, struct sched_domain *sd) update_group_power(sd, cpu); atomic_set(&sg->sgp->nr_busy_cpus, sg->group_weight); + clear_bit(NOHZ_IDLE, nohz_flags(cpu)); } int __weak arch_sd_sibling_asym_packing(void) -- 1.7.9.5
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