From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta-65-228.siemens.flowmailer.net (mta-65-228.siemens.flowmailer.net [185.136.65.228]) (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 59EA533062 for ; Wed, 23 Apr 2025 12:16:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.136.65.228 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745410570; cv=none; b=r4TYRDDxACvZZb1HMi2RcI/d5uI0LWJqfaxByA4nwWABUr38aVW2AZKkpaZtDJjcCOSANzd2tyIcJzpPrCp82PfR5AtijJIjrRP7/DcMHm/iH7KrHvNQ/toKQHe6O92pMZbHVue1epKMEWKZa9XGLRmCQ2GP9giA3L9dmMtwF0I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745410570; c=relaxed/simple; bh=qRoCsAChPe7q/2eN3nI2BTBi5wqWI0Ci+iYd84NLMGw=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=kJbweuiPEenyKchs9mMK4e63jRz6GWZ8a8hYd4dEDFjpOPjzzy8tLxfpmwNiZlyJEQzU1NtthCr3UkIgJY5yBBZyyn0FBeGSRvX2Pi/oB9rlGKI1BOYyoZeFzt/y1BE4SFpzm+FwHK+CZmn21SWsJj3L5sOTSJGFCAGqBB+3/S0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=siemens.com; spf=pass smtp.mailfrom=rts-flowmailer.siemens.com; dkim=pass (2048-bit key) header.d=siemens.com header.i=florian.bezdeka@siemens.com header.b=AFPe3gzP; arc=none smtp.client-ip=185.136.65.228 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=siemens.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rts-flowmailer.siemens.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=siemens.com header.i=florian.bezdeka@siemens.com header.b="AFPe3gzP" Received: by mta-65-228.siemens.flowmailer.net with ESMTPSA id 202504231215564751507c6a6c06f386 for ; Wed, 23 Apr 2025 14:15:56 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=fm2; d=siemens.com; i=florian.bezdeka@siemens.com; h=Date:From:Subject:To:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:Cc:References:In-Reply-To; bh=qRoCsAChPe7q/2eN3nI2BTBi5wqWI0Ci+iYd84NLMGw=; b=AFPe3gzPUeVMxVrZY9NuCBerTQj6tJ8byfbP9+nxdm6DiHPcG4pTr1uADB3a+yQMNy+nDq F9r4X11DlyG9mUHpyCWI6dFa0fkkANxWxSNumInawegfCMl6QM56AebY/6J3D+58d6qFtXuI xRG0gAT0knqhjrMruprSUIOnEotxRE03Eg+3D1XSRAK1NMRY9Nkz762CZsKOZ/3nO18SMOCj YMO/Hk0uGdWawZgr8wj8GiHVf1HUYZ/M1IyEAGGoPN0wkOfsGjo8qqBZH15kbxIGWfGHAENA /i/ZxOP0FCvB9WM4uwji+7qk2EqZFuwzqzl2WhjC1BFVJpQPISSj8M1A==; Message-ID: Subject: Re: [RFC PATCH v2 7/7] sched/fair: alternative way of accounting throttle time From: Florian Bezdeka To: Aaron Lu Cc: Valentin Schneider , Ben Segall , K Prateek Nayak , Peter Zijlstra , Josh Don , Ingo Molnar , Vincent Guittot , Xi Wang , linux-kernel@vger.kernel.org, Juri Lelli , Dietmar Eggemann , Steven Rostedt , Mel Gorman , Chengming Zhou , Chuyi Zhou , Jan Kiszka Date: Wed, 23 Apr 2025 14:15:55 +0200 In-Reply-To: <20250423112651.GA437160@bytedance> References: <20250409120746.635476-1-ziqianlu@bytedance.com> <20250409120746.635476-8-ziqianlu@bytedance.com> <099db50ce28f8b4bde37b051485de62a8f452cc2.camel@siemens.com> <20250418031550.GA1516180@bytedance> <87776d335eec8fe02b29d96818fd5c2dde5ed7af.camel@siemens.com> <20250423112651.GA437160@bytedance> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Flowmailer-Platform: Siemens Feedback-ID: 519:519-68982:519-21489:flowmailer On Wed, 2025-04-23 at 19:26 +0800, Aaron Lu wrote: > On Tue, Apr 22, 2025 at 05:03:19PM +0200, Florian Bezdeka wrote: > ... ... >=20 > > Right, I should have mentioned that crucial detail. Sorry. > >=20 > > I ported your series to 6.14.2 because we did/do not trust anything > > newer yet for testing. The problematic workload was not available in > > our lab at that time, so we had to be very carefully about deployed > > kernel versions. > >=20 > > I'm attaching the backported patches now, so you can compare / review > > if you like. Spoiler: The only differences are line numbers ;-) >=20 > I didn't notice any problem regarding backport after a quick look. >=20 > May I know what kind of workload triggered this warning? I haven't been > able to trigger it, I'll have to stare harder at the code. There are a couple of containers running. Nothing special as far as I can tell. Network, IO, at least one container heavily using the epoll interface. The system is still operating fine though... Once again: PREEMPT_RT enabled, so maybe handling an IRQ over the accounting code could happen? Looking at the warning again it looks like unthrottle_cfs_rq() is called from IRQ context. Is that expected? Best regards, Florian