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From: K Prateek Nayak <kprateek.nayak@amd.com>
To: Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Juri Lelli <juri.lelli@redhat.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	<linux-kernel@vger.kernel.org>
Cc: 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>,
	Chen Yu <yu.c.chen@intel.com>,
	Shrikanth Hegde <sshegde@linux.ibm.com>,
	"Gautham R. Shenoy" <gautham.shenoy@amd.com>,
	K Prateek Nayak <kprateek.nayak@amd.com>
Subject: [PATCH v3 1/8] sched/topology: Compute sd_weight considering cpuset partitions
Date: Tue, 20 Jan 2026 11:32:39 +0000	[thread overview]
Message-ID: <20260120113246.27987-2-kprateek.nayak@amd.com> (raw)
In-Reply-To: <20260120113246.27987-1-kprateek.nayak@amd.com>

The "sd_weight" used for calculating the load balancing interval, and
its limits, considers the span weight of the entire topology level
without accounting for cpuset partitions.

Compute the "sd_weight" after computing the "sd_span" considering the
cpu_map covered by the partition, and set the load balancing interval,
and its limits accordingly.

Fixes: cb83b629bae03 ("sched/numa: Rewrite the CONFIG_NUMA sched domain support")
Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
---
Changelog rfc v2..v3:

o New patch.
---
 kernel/sched/topology.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index cf643a5ddedd..649674bb6c3c 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1638,8 +1638,6 @@ sd_init(struct sched_domain_topology_level *tl,
 	int sd_id, sd_weight, sd_flags = 0;
 	struct cpumask *sd_span;
 
-	sd_weight = cpumask_weight(tl->mask(tl, cpu));
-
 	if (tl->sd_flags)
 		sd_flags = (*tl->sd_flags)();
 	if (WARN_ONCE(sd_flags & ~TOPOLOGY_SD_FLAGS,
@@ -1647,8 +1645,6 @@ sd_init(struct sched_domain_topology_level *tl,
 		sd_flags &= TOPOLOGY_SD_FLAGS;
 
 	*sd = (struct sched_domain){
-		.min_interval		= sd_weight,
-		.max_interval		= 2*sd_weight,
 		.busy_factor		= 16,
 		.imbalance_pct		= 117,
 
@@ -1668,7 +1664,6 @@ sd_init(struct sched_domain_topology_level *tl,
 					,
 
 		.last_balance		= jiffies,
-		.balance_interval	= sd_weight,
 
 		/* 50% success rate */
 		.newidle_call		= 512,
@@ -1685,6 +1680,11 @@ sd_init(struct sched_domain_topology_level *tl,
 	cpumask_and(sd_span, cpu_map, tl->mask(tl, cpu));
 	sd_id = cpumask_first(sd_span);
 
+	sd_weight = cpumask_weight(sd_span);
+	sd->min_interval = sd_weight;
+	sd->max_interval = 2 * sd_weight;
+	sd->balance_interval = sd_weight;
+
 	sd->flags |= asym_cpu_capacity_classify(sd_span, cpu_map);
 
 	WARN_ONCE((sd->flags & (SD_SHARE_CPUCAPACITY | SD_ASYM_CPUCAPACITY)) ==
-- 
2.34.1


  reply	other threads:[~2026-01-20 11:33 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-01-20 11:32 [PATCH v3 0/8] sched/topology: Optimize sd->shared allocation K Prateek Nayak
2026-01-20 11:32 ` K Prateek Nayak [this message]
2026-01-21 14:45   ` [PATCH v3 1/8] sched/topology: Compute sd_weight considering cpuset partitions Chen, Yu C
2026-01-21 15:42   ` Shrikanth Hegde
2026-01-22  2:51     ` K Prateek Nayak
2026-02-05 16:53   ` Valentin Schneider
2026-01-20 11:32 ` [PATCH v3 2/8] sched/topology: Allocate per-CPU sched_domain_shared in s_data K Prateek Nayak
2026-01-21 15:17   ` Chen, Yu C
2026-02-05 16:53   ` Valentin Schneider
2026-01-20 11:32 ` [PATCH v3 3/8] sched/topology: Switch to assigning "sd->shared" from s_data K Prateek Nayak
2026-01-21 15:26   ` Chen, Yu C
2026-01-22  2:49     ` K Prateek Nayak
2026-01-22  8:12   ` Shrikanth Hegde
2026-01-22  8:36     ` K Prateek Nayak
2026-01-23  4:08       ` Shrikanth Hegde
2026-01-23  4:53         ` K Prateek Nayak
2026-02-05 16:53   ` Valentin Schneider
2026-02-06  5:20     ` K Prateek Nayak
2026-02-06  9:38       ` Valentin Schneider
2026-02-14  3:04         ` Chen, Yu C
2026-02-16  3:50           ` K Prateek Nayak
2026-02-14  2:59       ` Chen, Yu C
2026-01-20 11:32 ` [PATCH v3 4/8] sched/topology: Remove sched_domain_shared allocation with sd_data K Prateek Nayak
2026-02-05 16:53   ` Valentin Schneider
2026-01-20 11:32 ` [PATCH v3 5/8] sched/core: Check for rcu_read_lock_any_held() in idle_get_state() K Prateek Nayak
2026-01-20 11:32 ` [PATCH v3 6/8] sched/fair: Remove superfluous rcu_read_lock() in the wakeup path K Prateek Nayak
2026-01-20 11:32 ` [PATCH v3 7/8] sched/fair: Simplify the entry condition for update_idle_cpu_scan() K Prateek Nayak
2026-02-14 15:41   ` Chen, Yu C
2026-01-20 11:32 ` [PATCH v3 8/8] sched/fair: Simplify SIS_UTIL handling in select_idle_cpu() K Prateek Nayak
2026-01-23  6:06   ` Shrikanth Hegde
2026-01-23  6:27     ` K Prateek Nayak
2026-01-23  7:14       ` Shrikanth Hegde
2026-02-14 15:56   ` Chen, Yu C
2026-01-21 16:16 ` [PATCH v3 0/8] sched/topology: Optimize sd->shared allocation Peter Zijlstra
2026-01-22  2:56   ` K Prateek Nayak
2026-01-23  9:54     ` Peter Zijlstra

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