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 32F2A27CB02 for ; Wed, 18 Mar 2026 15:01:39 +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=1773846100; cv=none; b=G9i6JdFDqWcBm1BHQMNZIEU88g5j9/JJ0kTC84FQ8EeoVLQBRmRGbLQjA6ckXqThmgqvUpD9R3r/6X0hSsCgZFKgyQwGafCmReKlR/TqJc8DbTCN+iHA9q8EAUdJIMsgliD0yGMevnf0q8tBzYx8jrlPT2UNjlqWIK3r2Lrnm0U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773846100; c=relaxed/simple; bh=PDS3mSpHW72uJII/44wlj6EpYYmM5pfCWYTLaAfZo9A=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=V/2jbxIBZaUrJdlkpcAu7NWUzWM9uJV31/bYl8I/bTFMEX95JMIRRtnMhJr3T4K+kTQceFa3D8fMGBrlGeHSI49blzkzLQeyP9VmqNG98QLVfDuLtVz4bvU0yCwnlv1tj2Nuaa+RbY2Fci9Mdb9ypmO6DIM5Cd5tCV7/wqW+7Mk= 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=P472dMGV; arc=none smtp.client-ip=90.155.92.199 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="P472dMGV" 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:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=jsZ/kaeKqsYN1sthUEytCCAUJMGZ4BRdJvg9dm7uxbo=; b=P472dMGVKR4PKfKfs5noDmI/K/ XbYW+C7FHD1jLBJ3csZBYcyCL91wtWyyyQMuzsk8N5DSa1CsW//RyG2T75nDmdpZQQhjEVd2dyKcP ssgYaEcaCvvurMEsg0A/EeFBE+Z1QUBAabKvdmRet1+P6BQEJaJRo9mAwfdDQ/RM539cH3Qvxicpn ML4cqZhvqEzYO3qm3ZyP1/5vbfLGwCaiJzOTMnH+JNYYhPN9z1ZNlVEQyk5OUL8WWxEVx9ut2/H2u fMe44mIfDpvAckQM/1ayhsASGDxFjAfDfaT22tbIp+39FZY9nlrRKZWwM3UyhS5zzAWvfEO+xgriU /dB7/+iQ==; 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 desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1w2sOp-0000000BUuS-1wMr; Wed, 18 Mar 2026 15:01:31 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 59901301BDE; Wed, 18 Mar 2026 15:53:15 +0100 (CET) Date: Wed, 18 Mar 2026 15:53:15 +0100 From: Peter Zijlstra To: Steven Rostedt Cc: Shrikanth Hegde , Joseph Salisbury , Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Ben Segall , Mel Gorman , Valentin Schneider , linux-kernel@vger.kernel.org Subject: Re: [PATCH] sched/core: initialize resched_latency in sched_tick() Message-ID: <20260318145315.GK3738010@noisy.programming.kicks-ass.net> References: <20260317195807.98850-1-joseph.salisbury@oracle.com> <20260317170943.44c41263@gandalf.local.home> <20260318104826.64ccbe09@gandalf.local.home> Precedence: bulk X-Mailing-List: linux-kernel@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: <20260318104826.64ccbe09@gandalf.local.home> On Wed, Mar 18, 2026 at 10:48:26AM -0400, Steven Rostedt wrote: > On Wed, 18 Mar 2026 12:00:58 +0530 > Shrikanth Hegde wrote: > > > Whats the relevance of resched_latency warnings in the age of preempt > > kernels being the default for majority of the archs. > > > > In case of full/lazy preemption, at the end of sched_tick itself we would call > > schedule if need_resched is set provided it was preemptible. > > > > It kind of makes sense for non preemptive kernels. But we have preemptoff and > > preemptirqoff tracers which one could use. (although may need a kernel build) > > > > What bugs is it catching these days? > > Good point. I've never used it. I guess the question is, does anyone? Google added that, Ben are you guys still needing that?