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From: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
To: Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	 Juri Lelli <juri.lelli@redhat.com>,
	 Vincent Guittot <vincent.guittot@linaro.org>,
	 Dietmar Eggemann <dietmar.eggemann@arm.com>,
	 Steven Rostedt <rostedt@goodmis.org>,
	Ben Segall <bsegall@google.com>,  Mel Gorman <mgorman@suse.de>,
	Valentin Schneider <vschneid@redhat.com>,
	 Tim C Chen <tim.c.chen@linux.intel.com>,
	Chen Yu <yu.c.chen@intel.com>,
	 Christian Loehle <christian.loehle@arm.com>,
	 K Prateek Nayak <kprateek.nayak@amd.com>,
	Barry Song <baohua@kernel.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
	 Andrea Righi <arighi@nvidia.com>, Len Brown <lenb@kernel.org>,
	 ricardo.neri@intel.com, linux-kernel@vger.kernel.org,
	 Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Subject: [PATCH v5 2/6] sched/fair: Also gate overloaded status update for SD_ASYM_CPUCAPACITY
Date: Mon, 22 Jun 2026 17:05:52 -0700	[thread overview]
Message-ID: <20260622-rneri-fix-cas-clusters-v5-2-19968f2d1497@linux.intel.com> (raw)
In-Reply-To: <20260622-rneri-fix-cas-clusters-v5-0-19968f2d1497@linux.intel.com>

The argument sg_overloaded of update_sg_lb_stats() is only consumed when
balancing at the root domain. It only makes sense to update it in such a
case. Commit 3229adbe7875 ("sched/fair: Do not compute overloaded status
unnecessarily during lb") updated the logic accordingly but missed the case
in which the root domain has the SD_ASYM_CPUCAPACITY flag. Fix this.

Fixes: 3229adbe7875 ("sched/fair: Do not compute overloaded status unnecessarily during lb")
Tested-by: Christian Loehle <christian.loehle@arm.com>
Reported-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
---
Changes in v5:
 * Added Tested-by tag from Christian. Thanks!

Changes in v4:
 * Introduced this patch.

Changes in v3:
 * N/A

Changes in v2:
 * N/A
---
 kernel/sched/fair.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 892abd7fcc18..31baa0000616 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -11863,7 +11863,9 @@ static inline void update_sg_lb_stats(struct lb_env *env,
 			/* Check for a misfit task on the cpu */
 			if (sgs->group_misfit_task_load < rq->misfit_task_load) {
 				sgs->group_misfit_task_load = rq->misfit_task_load;
-				*sg_overloaded = 1;
+
+				if (balancing_at_rd)
+					*sg_overloaded = 1;
 			}
 		} else if (env->idle && sched_reduced_capacity(rq, env->sd)) {
 			/* Check for a task running on a CPU with reduced capacity */

-- 
2.43.0


  parent reply	other threads:[~2026-06-22 23:55 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-23  0:05 [PATCH v5 0/6] sched: Fix cluster scheduling in the presence of asymmetric capacity Ricardo Neri
2026-06-23  0:05 ` [PATCH v5 1/6] sched/fair: Do not skip CPUs of similar capacity with busy SMT siblings Ricardo Neri
2026-06-23  7:13   ` Vincent Guittot
2026-06-24  5:25     ` Ricardo Neri
2026-06-23  0:05 ` Ricardo Neri [this message]
2026-06-23  7:14   ` [PATCH v5 2/6] sched/fair: Also gate overloaded status update for SD_ASYM_CPUCAPACITY Vincent Guittot
2026-06-23  0:05 ` [PATCH v5 3/6] sched/fair: Check CPU capacity before comparing group types during load balance Ricardo Neri
2026-06-23  0:05 ` [PATCH v5 4/6] sched/fair: Skip misfit load accounting when the destination CPU cannot help Ricardo Neri
2026-06-23  0:05 ` [PATCH v5 5/6] sched/fair: Allow load balancing between CPUs of identical capacity Ricardo Neri
2026-06-23  7:20   ` Vincent Guittot
2026-06-23  7:45     ` Christian Loehle
2026-06-24  5:25       ` Ricardo Neri
2026-06-26  0:11         ` Ricardo Neri
2026-06-26 14:50           ` Vincent Guittot
2026-06-27  2:02             ` Ricardo Neri
2026-06-29 15:35               ` Vincent Guittot
2026-06-29 15:54                 ` Rafael J. Wysocki (Intel)
2026-06-29 15:58                   ` Vincent Guittot
2026-06-29 16:32                     ` Ricardo Neri
2026-06-30  7:00                       ` Vincent Guittot
2026-06-26 15:20       ` Vincent Guittot
2026-06-27 19:07   ` Andrea Righi
2026-06-29 16:22     ` Ricardo Neri
2026-06-23  0:05 ` [PATCH v5 6/6] sched/topology: Do not clear SD_PREFER_SIBLING in domains with clusters Ricardo Neri
2026-06-23  7:26   ` Vincent Guittot
2026-06-24  5:14     ` Ricardo Neri
2026-06-26  0:19       ` Ricardo Neri
2026-06-26 14:54         ` Vincent Guittot
2026-06-29 13:10 ` [PATCH v5 0/6] sched: Fix cluster scheduling in the presence of asymmetric capacity Andrea Righi
2026-06-29 16:24   ` Ricardo Neri

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