From: Peter Zijlstra <peterz@infradead.org>
To: Chen Jinghuang <chenjinghuang2@huawei.com>
Cc: mingo@redhat.com, juri.lelli@redhat.com,
vincent.guittot@linaro.org, linux-kernel@vger.kernel.org,
bsegall@google.com, dietmar.eggemann@arm.com,
rostedt@goodmis.org, mgorman@suse.de, vschneid@redhat.com,
kprateek.nayak@amd.com, chenl311@chinatelecom.cn,
steve.sistare@oracle.com
Subject: Re: [RFC PATCH v5 0/9] steal tasks to improve CPU utilization
Date: Fri, 20 Mar 2026 09:53:25 +0100 [thread overview]
Message-ID: <20260320085325.GM3738786@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20260320055920.2518389-1-chenjinghuang2@huawei.com>
On Fri, Mar 20, 2026 at 05:59:11AM +0000, Chen Jinghuang wrote:
> When a CPU has no more CFS tasks to run, and idle_balance() fails to
> find a task, then attempt to steal a task from an overloaded CPU in the
> same LLC. Maintain and use a bitmap of overloaded CPUs to efficiently
> identify candidates. To minimize search time, steal the first migratable
> task that is found when the bitmap is traversed. For fairness, search
> for migratable tasks on an overloaded CPU in order of next to run.
This makes no sense. It is the task of newidle to get more work -- if
that is failing for you, then we should fix that, not build a second way
to get tasks.
next prev parent reply other threads:[~2026-03-20 8:53 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-20 5:59 Chen Jinghuang
2026-03-20 5:59 ` [RFC PATCH v5 1/9] sched: Provide sparsemask, a reduced contention bitmap Chen Jinghuang
2026-03-20 5:59 ` [RFC PATCH v5 2/9] sched/topology: Provide hooks to allocate data shared per LLC Chen Jinghuang
2026-03-20 5:59 ` [RFC PATCH v5 3/9] sched/topology: Provide cfs_overload_cpus bitmap Chen Jinghuang
2026-03-20 5:59 ` [RFC PATCH v5 4/9] sched/fair: Dynamically update cfs_overload_cpus Chen Jinghuang
2026-03-24 13:56 ` kernel test robot
2026-03-20 5:59 ` [RFC PATCH v5 5/9] sched/fair: Hoist idle_stamp up from idle_balance Chen Jinghuang
2026-03-20 5:59 ` [RFC PATCH v5 6/9] sched/fair: Generalize the detach_task interface Chen Jinghuang
2026-03-20 5:59 ` [RFC PATCH v5 7/9] sched/fair: Provide can_migrate_task_llc Chen Jinghuang
2026-03-20 5:59 ` [RFC PATCH v5 8/9] sched/fair: Steal work from an overloaded CPU when CPU goes idle Chen Jinghuang
2026-03-20 5:59 ` [RFC PATCH v5 9/9] sched/fair: Provide idle search schedstats Chen Jinghuang
2026-03-20 8:53 ` Peter Zijlstra [this message]
2026-03-27 13:54 ` [RFC PATCH v5 0/9] steal tasks to improve CPU utilization Valentin Schneider
2026-03-28 2:48 ` chenjinghuang
2026-04-20 4:01 ` chenjinghuang
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