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From: Yafang Shao <laoar.shao@gmail.com>
To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
	vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
	rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
	vschneid@redhat.com, kprateek.nayak@amd.com, gourry@gourry.net,
	david@kernel.org, tim.c.chen@linux.intel.com,
	yu.c.chen@intel.com
Cc: linux-kernel@vger.kernel.org, Yafang Shao <laoar.shao@gmail.com>
Subject: [PATCH 2/2] sched: use static_branch_likely() for the NUMA balancing tick check
Date: Fri, 23 Oct 2026 10:31:05 +0800	[thread overview]
Message-ID: <20261023023105.28829-3-laoar.shao@gmail.com> (raw)
In-Reply-To: <20261023023105.28829-1-laoar.shao@gmail.com>

task_tick_fair() checks sched_numa_balancing on every tick. The
static_branch_unlikely() annotation reserves the nop for the disabled case,
so the default configuration (NUMA_BALANCING_DEFAULT_ENABLED=y) pays a
taken jump per tick. Flip the polarity to static_branch_likely() so that
the fast path matches the default.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Gregory Price (Meta) <gourry@gourry.net>
---
 kernel/sched/fair.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 973647ad6c2d..71dc47d6114d 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -15351,7 +15351,7 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
 	if (queued)
 		return;
 
-	if (static_branch_unlikely(&sched_numa_balancing))
+	if (static_branch_likely(&sched_numa_balancing))
 		task_tick_numa(rq, curr);
 
 	task_tick_cache(rq, curr);
-- 
2.52.0


      parent reply	other threads:[~2026-10-23  2:31 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-23  2:31 [PATCH 0/2] sched: small changes Yafang Shao
2026-10-23  2:31 ` [PATCH 1/2] sched: fix stale get_pref_llc() stub for !CONFIG_SCHED_CACHE Yafang Shao
2026-10-23  2:31 ` Yafang Shao [this message]

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