When computing cache hot, we should check if the migration dst cpu is idle,
instead of the current cpu. Though they are same in normal balancing, that
is false nowadays in nohz idle balancing at least.
Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Mike Galbraith <mgalbraith@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140607090452.4696E301D2@webmail.sinamail.sina.com.cn
Signed-off-by: Ingo Molnar <mingo@kernel.org>
/*
* Is this task likely cache-hot:
*/
/*
* Is this task likely cache-hot:
*/
-static int
-task_hot(struct task_struct *p, u64 now)
+static int task_hot(struct task_struct *p, struct lb_env *env)
/*
* Buddy candidates are cache hot:
*/
/*
* Buddy candidates are cache hot:
*/
- if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running &&
+ if (sched_feat(CACHE_HOT_BUDDY) && env->dst_rq->nr_running &&
(&p->se == cfs_rq_of(&p->se)->next ||
&p->se == cfs_rq_of(&p->se)->last))
return 1;
(&p->se == cfs_rq_of(&p->se)->next ||
&p->se == cfs_rq_of(&p->se)->last))
return 1;
if (sysctl_sched_migration_cost == 0)
return 0;
if (sysctl_sched_migration_cost == 0)
return 0;
- delta = now - p->se.exec_start;
+ delta = rq_clock_task(env->src_rq) - p->se.exec_start;
return delta < (s64)sysctl_sched_migration_cost;
}
return delta < (s64)sysctl_sched_migration_cost;
}
* 2) task is cache cold, or
* 3) too many balance attempts have failed.
*/
* 2) task is cache cold, or
* 3) too many balance attempts have failed.
*/
- tsk_cache_hot = task_hot(p, rq_clock_task(env->src_rq));
+ tsk_cache_hot = task_hot(p, env);
if (!tsk_cache_hot)
tsk_cache_hot = migrate_degrades_locality(p, env);
if (!tsk_cache_hot)
tsk_cache_hot = migrate_degrades_locality(p, env);