From: Peter Zijlstra <peterz@infradead.org>
To: Aaron Tomlin <atomlin@atomlin.com>
Cc: mingo@redhat.com, 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, neelx@suse.com,
sean@ashe.io, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sched/debug: Introduce per-CPU debugfs files
Date: Tue, 28 Jul 2026 12:48:49 +0200 [thread overview]
Message-ID: <20260728104849.GI49951@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20260728020309.6169-1-atomlin@atomlin.com>
On Mon, Jul 27, 2026 at 10:03:09PM -0400, Aaron Tomlin wrote:
> Currently, accessing scheduler debugging details for a specific CPU
> requires reading /sys/kernel/debug/sched/debug, which outputs
> information for all online CPUs. This results in redundant output and
> parsing overhead on large SMP systems when targeting an individual CPU.
>
> Add support for per-CPU debug files under:
> /sys/kernel/debug/sched/cpu/cpu<N>/debug. Reading
> /sys/kernel/debug/sched/cpu/cpu<N>/debug calls print_cpu() specifically
> for CPU <N>, exposing CPU-specific runqueue details on demand.
You're failing to explain why though. In what situation does the
overhead from sched/debug matter one whit? If you're dumping this at
frequencies high enough for this to matter, you're doing something
terribly wrong.
next prev parent reply other threads:[~2026-07-28 10:49 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-28 2:03 [PATCH] sched/debug: Introduce per-CPU debugfs files Aaron Tomlin
2026-07-28 6:34 ` Zhan Xusheng
2026-07-28 13:21 ` Aaron Tomlin
2026-07-28 10:48 ` Peter Zijlstra [this message]
2026-07-28 13:37 ` Daniel Vacek
2026-07-28 13:42 ` Aaron Tomlin
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