From: Valentin Schneider <valentin.schneider@arm.com>
To: linux-kernel@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Qais Yousef <qais.yousef@arm.com>,
Quentin Perret <qperret@google.com>,
Pavan Kondeti <pkondeti@codeaurora.org>,
Rik van Riel <riel@surriel.com>
Subject: [PATCH 4/8] sched/fair: Use dst_cpu's capacity rather than group {min, max} capacity
Date: Thu, 28 Jan 2021 18:31:37 +0000 [thread overview]
Message-ID: <20210128183141.28097-5-valentin.schneider@arm.com> (raw)
In-Reply-To: <20210128183141.28097-1-valentin.schneider@arm.com>
Comparing capacity extrema of local and source sched_group's doesn't make
much sense when at the day of the day the imbalance will be pulled by a
known env->dst_cpu, whose capacity can be anywhere within the local group's
capacity extrema.
Replace group_smaller_{min, max}_cpu_capacity() with comparisons of the
source group's min/max capacity and the destination CPU's capacity.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
---
kernel/sched/fair.c | 31 +++----------------------------
1 file changed, 3 insertions(+), 28 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 58ce0b22fcb0..0959a770ecc0 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -8352,26 +8352,6 @@ group_is_overloaded(unsigned int imbalance_pct, struct sg_lb_stats *sgs)
return false;
}
-/*
- * group_smaller_min_cpu_capacity: Returns true if sched_group sg has smaller
- * per-CPU capacity than sched_group ref.
- */
-static inline bool
-group_smaller_min_cpu_capacity(struct sched_group *sg, struct sched_group *ref)
-{
- return capacity_greater(ref->sgc->min_capacity, sg->sgc->min_capacity);
-}
-
-/*
- * group_smaller_max_cpu_capacity: Returns true if sched_group sg has smaller
- * per-CPU capacity_orig than sched_group ref.
- */
-static inline bool
-group_smaller_max_cpu_capacity(struct sched_group *sg, struct sched_group *ref)
-{
- return capacity_greater(ref->sgc->max_capacity, sg->sgc->max_capacity);
-}
-
static inline enum
group_type group_classify(unsigned int imbalance_pct,
struct sched_group *group,
@@ -8523,15 +8503,10 @@ static bool update_sd_pick_busiest(struct lb_env *env,
if (!sgs->sum_h_nr_running)
return false;
- /*
- * Don't try to pull misfit tasks we can't help.
- * We can use max_capacity here as reduction in capacity on some
- * CPUs in the group should either be possible to resolve
- * internally or be covered by avg_load imbalance (eventually).
- */
+ /* Don't try to pull misfit tasks we can't help */
if (static_branch_unlikely(&sched_asym_cpucapacity) &&
sgs->group_type == group_misfit_task &&
- (!group_smaller_max_cpu_capacity(sg, sds->local) ||
+ (!capacity_greater(capacity_of(env->dst_cpu), sg->sgc->max_capacity) ||
sds->local_stat.group_type != group_has_spare))
return false;
@@ -8615,7 +8590,7 @@ static bool update_sd_pick_busiest(struct lb_env *env,
*/
if (sd_has_asym_cpucapacity(env->sd) &&
(sgs->group_type <= group_fully_busy) &&
- (group_smaller_min_cpu_capacity(sds->local, sg)))
+ (capacity_greater(sg->sgc->min_capacity, capacity_of(env->dst_cpu))))
return false;
return true;
--
2.27.0
next prev parent reply other threads:[~2021-01-28 18:35 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-28 18:31 [PATCH 0/8] sched/fair: misfit task load-balance tweaks Valentin Schneider
2021-01-28 18:31 ` [PATCH 1/8] sched/fair: Clean up active balance nr_balance_failed trickery Valentin Schneider
2021-02-03 15:14 ` Qais Yousef
2021-02-03 18:42 ` Valentin Schneider
2021-02-04 15:05 ` Qais Yousef
2021-02-05 13:51 ` Vincent Guittot
2021-02-05 14:05 ` Valentin Schneider
2021-02-05 14:34 ` Vincent Guittot
2021-01-28 18:31 ` [PATCH 2/8] sched/fair: Add more sched_asym_cpucapacity static branch checks Valentin Schneider
2021-02-03 15:14 ` Qais Yousef
2021-02-09 8:42 ` Vincent Guittot
2021-01-28 18:31 ` [PATCH 3/8] sched/fair: Tweak misfit-related capacity checks Valentin Schneider
2021-02-03 15:15 ` Qais Yousef
2021-02-03 18:42 ` Valentin Schneider
2021-02-05 14:31 ` Vincent Guittot
2021-02-05 16:59 ` Valentin Schneider
2021-02-05 17:17 ` Vincent Guittot
2021-02-05 20:07 ` Valentin Schneider
2021-02-08 15:29 ` Vincent Guittot
2021-02-08 17:49 ` Valentin Schneider
2021-01-28 18:31 ` Valentin Schneider [this message]
2021-02-03 15:15 ` [PATCH 4/8] sched/fair: Use dst_cpu's capacity rather than group {min, max} capacity Qais Yousef
2021-01-28 18:31 ` [PATCH 5/8] sched/fair: Make check_misfit_status() only compare dynamic capacities Valentin Schneider
2021-02-03 15:15 ` Qais Yousef
2021-02-04 10:49 ` Dietmar Eggemann
2021-02-04 11:34 ` Valentin Schneider
2021-02-04 14:57 ` Dietmar Eggemann
2021-01-28 18:31 ` [PATCH 6/8] sched/fair: Filter out locally-unsolvable misfit imbalances Valentin Schneider
2021-02-03 15:16 ` Qais Yousef
2021-02-03 18:43 ` Valentin Schneider
2021-01-28 18:31 ` [PATCH 7/8] sched/fair: Attempt misfit active balance when migration_type != migrate_misfit Valentin Schneider
2021-02-03 15:16 ` Qais Yousef
2021-02-03 18:43 ` Valentin Schneider
2021-02-04 11:44 ` Dietmar Eggemann
2021-02-04 12:22 ` Valentin Schneider
2021-02-09 8:58 ` Vincent Guittot
2021-02-09 18:19 ` Valentin Schneider
2021-01-28 18:31 ` [PATCH 8/8] sched/fair: Relax task_hot() for misfit tasks Valentin Schneider
2021-02-03 15:17 ` Qais Yousef
2021-02-08 16:21 ` Vincent Guittot
2021-02-08 18:24 ` Valentin Schneider
2021-02-09 8:56 ` Vincent Guittot
2021-02-03 15:14 ` [PATCH 0/8] sched/fair: misfit task load-balance tweaks Qais Yousef
2021-02-03 18:43 ` Valentin Schneider
2021-02-04 12:03 ` Dietmar Eggemann
2021-02-04 12:36 ` Valentin Schneider
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