From: Tejun Heo <tj@kernel.org>
To: Aaron Tomlin <atomlin@atomlin.com>
Cc: jiangshanlai@gmail.com, rostedt@goodmis.org, mhiramat@kernel.org,
osandov@osandov.com, neelx@suse.com, sean@ashe.io,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH 0/3] workqueue: Add telemetry tracepoints for CPU hogs, distress, and BH budget yields
Date: Mon, 31 Aug 2026 11:08:02 -1000 [thread overview]
Message-ID: <652a415f83f59c4f13716367e7081523@kernel.org> (raw)
In-Reply-To: <20260829230517.42468-1-atomlin@atomlin.com>
Hello, Aaron.
On Sat, Aug 29, 2026 at 07:05:14PM -0400, Aaron Tomlin wrote:
> This patch series introduces lightweight tracepoints for these key
> operational boundaries:
Lai's address was mangled in the cc list. Corrected to
jiangshanlai@gmail.com.
Generally looks fine to me. Some comments:
- As the test robot reported, the open-coded u64 division in the first
patch breaks 32bit builds. Rather than restructuring the comparison,
it'd be better to keep it as-is and calculate the duration only after
the worker is marked CPU_INTENSIVE. That also keeps the division out
of the every-tick path.
- In the third patch, the timeout flag is determined by re-reading
jiffies after the loop. If the loop exited because nr_restarts ran
out, time_before() was never tested and a tick in that window would
misattribute the yield to timeout. Please derive the reason from the
condition that actually terminated the loop. Also, BH_WORKER_RESTARTS
- nr_restarts counts loop iterations, not restarts.
Thanks.
--
tejun
prev parent reply other threads:[~2026-08-31 21:08 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-29 23:05 [PATCH 0/3] workqueue: Add telemetry tracepoints for CPU hogs, distress, and BH budget yields Aaron Tomlin
2026-08-29 23:05 ` [PATCH 1/3] workqueue: Add workqueue_cpu_intensive tracepoint Aaron Tomlin
2026-08-29 23:14 ` sashiko-bot
2026-08-29 23:05 ` [PATCH 2/3] workqueue: Add workqueue_mayday and workqueue_rescued tracepoints Aaron Tomlin
2026-08-29 23:05 ` [PATCH 3/3] workqueue: Add workqueue_bh_budget_yield tracepoint Aaron Tomlin
2026-08-31 17:41 ` kernel test robot
2026-08-31 21:08 ` Tejun Heo [this message]
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