Re: [ANNOUNCE] 4.4-rc6-rt1
From: Thomas Gleixner <hidden>
Date: 2016-01-16 13:44:39
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On Sat, 16 Jan 2016, Mike Galbraith wrote:
On Thu, 2016-01-14 at 17:05 +0100, Mike Galbraith wrote:quoted
This is virgin -rt1 modulo fixlet applied to v4.4.0, built with the .config from v4.4.0 that built it (modulo RT_FULL) rebuilding itself via make -j8. homer:/root # vmstat 10 procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 0 1 0 14742988 179832 680792 0 0 634 25 326 1196 2 1 89 8 0 8 0 0 14476084 179848 701632 0 0 814 525 2421 12314 11 1 87 1 0 8 0 0 14483232 179864 712656 0 0 165 1628 2404 12320 11 1 87 1 0 8 0 0 14493336 180008 727836 0 0 141 762 2328 11306 11 1 87 0 0 8 0 0 14456436 180024 738356 0 0 159 1478 2336 11939 11 1 87 0 0 Way too idle, taking forever.It now being the weekend... sched: Disable default set_cpus_allowed() method during update_migrate_disable(). update_migrate_disable() calls class::set_cpus_allowed(), when that method is set_cpus_allowed_common(), writing to ->cpus_allowed defeats the intent of migrate_disable(), permanently disabling migration instead.
Ha, you found it as well :)
quoted hunk ↗ jump to hunk
Signed-off-by: Mike Galbraith <redacted> --- kernel/sched/core.c | 2 ++ 1 file changed, 2 insertions(+)--- a/kernel/sched/core.c +++ b/kernel/sched/core.c@@ -1205,6 +1205,8 @@ static int migration_cpu_stop(void *data */ void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask) { + if (__migrate_disabled(p)) + return; cpumask_copy(&p->cpus_allowed, new_mask); p->nr_cpus_allowed = cpumask_weight(new_mask); }