From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 9A182270EC5; Tue, 19 Aug 2025 10:14:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755598467; cv=none; b=N+LVGShbEW7lJciCi3VGc/eWODqDklog7gn1m8qLVX5weNro91Ml/eBULMyXtRkxevZHXEBG/nXvfusRZLV40ztJ6Rt9BXDMWjveFS8h2YXTMSRz7oPC7VvodP/vBTzxiuMx0j4Ty6Ded3+h1rJ69nDL8TQCRSrPIGi+v5G4kKw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755598467; c=relaxed/simple; bh=4fXsy2RwHnxDypPVftvAWzSLgWnxEwSKYpqfwfOOj/I=; h=Date:From:To:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=efccFLrUB6nC3oQOifOJCjiqIDBkNKi/+7Thqj1d8PDVdcfGjwuJUNEn7HYHHQIT2GK75q0cDyPq3+DieUFCK51JkFKvkBi2xsS8VC9KKm9d2XF0rd7+j8HyFQCY8VrCG3plZajVu/ZBvG1ls7rHJ8Dgqy2maswidPZApcgkKIM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=gU1d41wL; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="gU1d41wL" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:To:From:Date:Sender:Reply-To:Cc: Content-Transfer-Encoding:Content-ID:Content-Description; bh=jTfFk0o9rkuryxDLznvP8p5NG9ZmamSXJKO8t6aHeGQ=; b=gU1d41wL3lESKmZWr/806Po0Th 8VyGEh1Wz0H1Z0wvpJlkwMG0IytzEILT4hLjIQSYOyhMsmHmI3MK25xcSwN3s7dr3eJYOPKMe75Pz o2+f5CtXqku7AoMBbITculoTQXmuFKOLFjMidphYw+VXG+mYxrWLCptzeFj0fq0LHSxDDqAGcNcfb gKOgS7+6e/NGKlxOhYSRYGRDBk5cBkKChMmvwffU7Br65aGLQQ/L94ouQ2CPD4z6Pfa8O2X5r01oi xZNPz3bS9mbKNSz/NjbeBfqRTY9OwYQ87gE6yvLwVlrqrZEOzGKrmB4+6u5C9Vf575v97jbZrcKH5 oSA83fuw==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1uoJM4-000000000ih-0DQq; Tue, 19 Aug 2025 10:14:12 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 5F6B030036F; Tue, 19 Aug 2025 12:14:11 +0200 (CEST) Date: Tue, 19 Aug 2025 12:14:11 +0200 From: Peter Zijlstra To: akpm@linux-foundation.org, wang.yaxin@zte.com.cn, fan.yu9@zte.com.cn, corbet@lwn.net, bsingharora@gmail.com, yang.yang29@zte.com.cn, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, 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, jiang.kun2@zte.com.cn, xu.xin16@zte.com.cn, wang.yong12@zte.com.cn, zyhtheonly@gmail.com, zyhtheonly@yeah.net Subject: Re: [PATCH] delayacct/sched: add SOFTIRQ delay Message-ID: <20250819101411.GG4067720@noisy.programming.kicks-ass.net> References: <20250819092739.GA31177@didi-ThinkCentre-M930t-N000> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250819092739.GA31177@didi-ThinkCentre-M930t-N000> On Tue, Aug 19, 2025 at 05:27:39PM +0800, Tio Zhang wrote: > Intro SOFTIRQ delay, so we can separate softirq as SOFTIRQ delay > and hardirq as {IRQ - SOFTIRQ} delay. > > A typical scenario is when tasks delayed by network, > if they delayed by rx net packets, i.e, net_rx_action(), > SOFTIRQ delay is almost same as IRQ delay; > if they delayed by, e.g, bad driver or broken hardware, > SOFTIRQ delay is almost 0 while IRQ delay remains big. > > Examples tool usage could be found in > Documentation/accounting/delay-accounting.rst accounting will be the death of us :/ How do you account ksoftirqd ?