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authorVincent Guittot <vincent.guittot@linaro.org>2019-10-18 15:26:35 +0200
committerIngo Molnar <mingo@kernel.org>2019-10-21 09:40:54 +0200
commitc63be7be59de65d12ff7b4329acea99cf734d6de (patch)
tree674796f49c976cd264cab1704c2b755647da22c5 /kernel/sched
parentsched/fair: Spread out tasks evenly when not overloaded (diff)
downloadlinux-dev-c63be7be59de65d12ff7b4329acea99cf734d6de.tar.xz
linux-dev-c63be7be59de65d12ff7b4329acea99cf734d6de.zip
sched/fair: Use utilization to select misfit task
Utilization is used to detect a misfit task but the load is then used to select the task on the CPU which can lead to select a small task with high weight instead of the task that triggered the misfit migration. Check that task can't fit the CPU's capacity when selecting the misfit task instead of using the load. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Acked-by: Valentin Schneider <valentin.schneider@arm.com> Cc: Ben Segall <bsegall@google.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Galbraith <efault@gmx.de> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: hdanton@sina.com Cc: parth@linux.ibm.com Cc: pauld@redhat.com Cc: quentin.perret@arm.com Cc: riel@surriel.com Cc: srikar@linux.vnet.ibm.com Link: https://lkml.kernel.org/r/1571405198-27570-9-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
-rw-r--r--kernel/sched/fair.c11
1 files changed, 3 insertions, 8 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index f489f603f317..1fd6f3917fe7 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7408,13 +7408,8 @@ static int detach_tasks(struct lb_env *env)
break;
case migrate_misfit:
- load = task_h_load(p);
-
- /*
- * Load of misfit task might decrease a bit since it has
- * been recorded. Be conservative in the condition.
- */
- if (load/2 < env->imbalance)
+ /* This is not a misfit task */
+ if (task_fits_capacity(p, capacity_of(env->src_cpu)))
goto next;
env->imbalance = 0;
@@ -8358,7 +8353,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
if (busiest->group_type == group_misfit_task) {
/* Set imbalance to allow misfit tasks to be balanced. */
env->migration_type = migrate_misfit;
- env->imbalance = busiest->group_misfit_task_load;
+ env->imbalance = 1;
return;
}