From: Peter Zijlstra <peterz@infradead.org>
To: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: linux-kernel@vger.kernel.org, mingo@kernel.org,
juri.lelli@redhat.com, vincent.guittot@linaro.org,
yury.norov@gmail.com, kprateek.nayak@amd.com, iii@linux.ibm.com,
corbet@lwn.net, tglx@kernel.org, gregkh@linuxfoundation.org,
pbonzini@redhat.com, seanjc@google.com, vschneid@redhat.com,
huschle@linux.ibm.com, rostedt@goodmis.org,
dietmar.eggemann@arm.com, maddy@linux.ibm.com,
srikar@linux.ibm.com, hdanton@sina.com, chleroy@kernel.org,
vineeth@bitbyteword.org, frederic@kernel.org, arighi@nvidia.com,
pauld@redhat.com, christian.loehle@arm.com, tj@kernel.org,
tommaso.cucinotta@gmail.com, maz@kernel.org, rafael@kernel.org,
rdunlap@infradead.org, kernellwp@gmail.com,
linux-doc@vger.kernel.org
Subject: Re: [PATCH v5 09/24] sched/fair: Pull the load on preferred CPU
Date: Fri, 26 Jun 2026 12:00:43 +0200 [thread overview]
Message-ID: <20260626100043.GP1181229@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20260625124648.802832-10-sshegde@linux.ibm.com>
On Thu, Jun 25, 2026 at 06:16:33PM +0530, Shrikanth Hegde wrote:
> @@ -14375,6 +14379,10 @@ static int sched_balance_newidle(struct rq *this_rq, struct rq_flags *rf)
> if (!cpu_active(this_cpu))
> return 0;
>
> + /* Do not pull to a !preferred CPU just to push it out next */
> + if (!cpu_preferred(this_cpu))
> + return 0;
> +
> /*
> * This is OK, because current is on_cpu, which avoids it being picked
> * for load-balance and preemption/IRQs are still disabled avoiding
Why not just replace the cpu_active() check above?
next prev parent reply other threads:[~2026-06-26 10:00 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-25 12:46 [PATCH v5 00/24] sched: Introduce cpu_preferred_mask and steal-driven vCPU backoff Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 01/24] sched/debug: Remove unused schedstats Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 02/24] sched/docs: Document cpu_preferred_mask and Preferred CPU concept Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 03/24] kconfig: Provide PREFERRED_CPU option Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 04/24] cpumask: Introduce cpu_preferred_mask Shrikanth Hegde
2026-06-26 9:34 ` Peter Zijlstra
2026-06-26 13:37 ` Shrikanth Hegde
2026-06-26 9:39 ` Peter Zijlstra
2026-06-26 9:41 ` Peter Zijlstra
2026-06-26 13:09 ` Shrikanth Hegde
2026-06-26 13:18 ` Yury Norov
2026-06-26 13:27 ` Shrikanth Hegde
2026-06-26 12:40 ` Yury Norov
2026-06-26 13:18 ` Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 05/24] sysfs: Add preferred CPU file Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 06/24] sched/core: allow only preferred CPUs in is_cpu_allowed Shrikanth Hegde
2026-06-26 13:06 ` Yury Norov
2026-06-26 13:25 ` Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 07/24] sched/fair: Select preferred CPU at wakeup when possible Shrikanth Hegde
2026-06-26 9:59 ` Peter Zijlstra
2026-06-26 13:17 ` Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 08/24] sched/fair: load balance only among preferred CPUs Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 09/24] sched/fair: Pull the load on preferred CPU Shrikanth Hegde
2026-06-26 10:00 ` Peter Zijlstra [this message]
2026-06-26 13:35 ` Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 10/24] sched/core: Keep tick on non-preferred CPUs until tasks are out Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 11/24] sched/core: Push current task from non preferred CPU Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 12/24] sched/debug: Add migration stats due to non preferred CPUs Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 13/24] virt/steal_monitor: Add documentation Shrikanth Hegde
2026-06-25 17:00 ` Randy Dunlap
2026-06-26 4:30 ` Shrikanth Hegde
2026-06-26 9:28 ` Peter Zijlstra
2026-06-26 14:05 ` Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 14/24] virt: Introduce steal monitor driver Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 15/24] virt/steal_monitor: Restore to active on module disable Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 16/24] virt/steal_monitor: Define steal_monitor structure Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 17/24] virt/steal_monitor: Add control knobs for handling steal values Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 18/24] virt/steal_monitor: Compute work at regular intervals Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 19/24] virt/steal_monitor: Provide default method to get systemwide steal time Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 20/24] virt/steal_monitor: Provide default method to inc/dec preferred CPUs Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 21/24] virt/steal_monitor: Provide default method to get num of CPUs for steal ratio Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 22/24] virt/steal_monitor: Act on steal values at regular intervals Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 23/24] virt/steal_monitor: Add direction control Shrikanth Hegde
2026-06-25 12:46 ` [PATCH v5 24/24] virt/steal_monitor: Add design check of preferred subset of active Shrikanth Hegde
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