From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E6B0639A7E0; Mon, 31 Aug 2026 21:08:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788210485; cv=none; b=O9aDZokVlVlLibSIwd7SebnfpcobAWbGvAH/aCIlHvhcYBZEuwdE6eGIz9jnrQ+d0zfSZSD20i0bbArum6vryz13k+fnPSxgshdRdjswFk1z4T6tEwUam64BlUzV4LtrLElyRotJQMyeXoHX7T5VM4ANOjMCZASCMgbUOhiavSk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788210485; c=relaxed/simple; bh=gvC3ju/HglQkrViKAOWT2imoCWUjJmIa21VpRNi0YMw=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References; b=Xcq1chaepf8hjG2kZVMZ4eeS6gPk7RqaLHKvx4klehR/JdciGsTxI7jL5h01tdfTIo0MK1AcvooWs3wfQ5gNYlXZq4ROYuqyvzuNuuFWeGp0mmCk1a+1Gihg8Ctzn7EANx0OyhBf3ZiGB5/sFDUikql2cMIcVfDI58PSmZ41/B8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QFq+Dx1A; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QFq+Dx1A" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 526AD1F00A3D; Mon, 31 Aug 2026 21:08:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788210483; bh=4+em0ZEdjHu4ShaBifn99b5fw4zGxldy7vlQoFRY6+0=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=QFq+Dx1AcUrcJe6kRtR/xQ6mw8BW+MVhJ54B1eyd7GdKaT66AGYDwZFVA6uAv8d7U 3LXFa27AyLTuuoiB7ZQbdIcjZ2TYBavqCq4aWYnxpwnhfO9Jl7GkYOa/hIma6amLnh XGcm2Wg/GUb/7TlkoVBYyMfM2EyoEEPOW7h/ftO2b+Sn0dsJ67OGLVOB3lsKtcKmUX ZX3YKjLByDII4odnLdaOshdjpyrKXvQWMUACPk6SffDuPRMGpo51EaJzegbjpYU5mx 3nmg4KGuP64rEPMG0Z2TYSe4JPBZMMNJQiV33Kia+H6bvyaBwPZCbb7Qbj6Pb+gPsR tiJG5RcXNYHwQ== Date: Mon, 31 Aug 2026 11:08:02 -1000 Message-ID: <652a415f83f59c4f13716367e7081523@kernel.org> From: Tejun Heo To: Aaron Tomlin 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 In-Reply-To: <20260829230517.42468-1-atomlin@atomlin.com> References: <20260829230517.42468-1-atomlin@atomlin.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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