From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 9DB4138BF99; Tue, 13 Jan 2026 11:56:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768305390; cv=none; b=p44PAeumjONv5/+ugFC0ig5eL3Ffl+slMOilCKVTk1UmERmPkFO0zN9d89Lj1XhPrLYX2RbCoFyrx2+d4CLdDyleAAiXj/KWVxLGon3qnqfre55rItmWRm4/aJiOzbe37fOlfLvhdQMLX3mezI5Rqi1B3Hweu5j9kz8kdglLBkk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768305390; c=relaxed/simple; bh=PLINpjm7eUCp1HsiKUyIP4tyjri37fh+wD1dDfgZ1d0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=m0sMPVOOuSzbELUQOEnmZ2OqLVjWWm/iI0s3eYHqayne4RDjIknJ4P60elEGkHMyQCXszZM+f9mH1rK9byf3yY/B0P+3zCGomAt8FJH86hvLnwokDafPlBgmTbZ81v6QCfwMawX/GEl9rmWEp6M+7wRQpEE88eTTZw5pFWUdz74= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (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=eWz50Dd1; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (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="eWz50Dd1" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=4Z3s2IJr2MRvr+ihpTUvHpk2NWB1i3v1041MBc/NhTo=; b=eWz50Dd1vGagt/tZizYceGdgz2 YisyKS9vruWQeSnN/Bh0mfdMXNjHtOTUAVyqRUG4UWXd4iXqr2JE+UAN/DgHjn8y/G0O1DRoBmmSi yDtyEYqvfhA5wqnh7W4agOZ+jDf+Xuz8OoIGf4BCPCU6tSLUmctNofXD2D7dHh9Ri5SwNjvSQhZD7 fDoAJmspfeM/kElDT5U74eEW8u5IrhjCqiyjWJcgz99PlUVbeZZklW4xRd0tb2cX66Z9DMjoG3YIG NZ7owagkXQrjpqWN65ekIFX9nmWPgSTA9toXlLK7A68fqYLUR139y5lowj4YglPXF2Pw6SyN/ZFeW HQn4Gjyw==; Received: from 2001-1c00-8d85-5700-266e-96ff-fe07-7dcc.cable.dynamic.v6.ziggo.nl ([2001:1c00:8d85:5700:266e:96ff:fe07:7dcc] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vfd0Y-00000004fWO-2lwm; Tue, 13 Jan 2026 11:56:22 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 3B27730049A; Tue, 13 Jan 2026 12:56:22 +0100 (CET) Date: Tue, 13 Jan 2026 12:56:22 +0100 From: Peter Zijlstra To: K Prateek Nayak Cc: Pierre Gondois , tj@kernel.org, linux-kernel@vger.kernel.org, mingo@kernel.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, longman@redhat.com, hannes@cmpxchg.org, mkoutny@suse.com, void@manifault.com, arighi@nvidia.com, changwoo@igalia.com, cgroups@vger.kernel.org, sched-ext@lists.linux.dev, liuwenfang@honor.com, tglx@linutronix.de, Christian Loehle Subject: Re: [PATCH 05/12] sched: Move sched_class::prio_changed() into the change pattern Message-ID: <20260113115622.GA831285@noisy.programming.kicks-ass.net> References: <20251006104402.946760805@infradead.org> <20251006104527.083607521@infradead.org> <717a0743-6d8f-4e35-8f2f-70a158b31147@arm.com> <20260113115309.GB831050@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: cgroups@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: <20260113115309.GB831050@noisy.programming.kicks-ass.net> On Tue, Jan 13, 2026 at 12:53:09PM +0100, Peter Zijlstra wrote: > On Tue, Jan 13, 2026 at 04:35:02PM +0530, K Prateek Nayak wrote: > > > Does enabling WARN_DOUBLE_CLOCK warn of a double clock update before > > hitting this warning? > > setup_new_dl_entity() -> update_rq_clock() seems like it will trip that > in this case. Something like so to fix: 9f239df55546 ("sched/deadline: Initialize dl_servers after SMP") --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -752,8 +752,6 @@ static inline void setup_new_dl_entity(s struct dl_rq *dl_rq = dl_rq_of_se(dl_se); struct rq *rq = rq_of_dl_rq(dl_rq); - update_rq_clock(rq); - WARN_ON(is_dl_boosted(dl_se)); WARN_ON(dl_time_before(rq_clock(rq), dl_se->deadline)); @@ -1834,6 +1832,7 @@ void sched_init_dl_servers(void) rq = cpu_rq(cpu); guard(rq_lock_irq)(rq); + update_rq_clock(rq); dl_se = &rq->fair_server;