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 C45F114375D for ; Wed, 16 Apr 2025 12:44:55 +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=1744807497; cv=none; b=cxBwT9i8vM0C3TB8syEdCHhat6EvahU4AqmgrExNH8dGHAbFyJvqvIavbBfent4kz9At19oAY2e/rlJR5XoXTf7A7hvoKAT5THA8JLzrN64Ujzc9jqKRDWJj6haUG8TjG3mdns9o2zj5z3Q3ScaW4ajkXFehtqSJf09IaqeKLzY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744807497; c=relaxed/simple; bh=iQI0suf2tPTWplb89dXtzsiwVQb48SdrkOXVSSSSHBc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=u+KKovcZyyW6DrDqIXDmUj4Nem6s9asFGuOrcWAgNFaoR2CpIzf2XWPi4gXRIAj4jjUcniMRhaggQnWITUq56gd/lx8ZATK19u5o44cuIwAErIlHl12OPj/1YmTip9cbOAjFrqUY3/LwOzFnQd0oLLuxRyuhy5fE3zAvRl22KJs= 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=QG0GxTS/; arc=none smtp.client-ip=90.155.50.34 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="QG0GxTS/" 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=5wYF1SvPeXU/zC/FYEGtuzfUCWUok7qhuSTquOTok7g=; b=QG0GxTS/6in7keqj9PKcgQBEUN UF9s1JUnLVl+7aoIBS3jwLFJZUEdI5YAom0KN4txW8GPKjb9uxevVLhhxZKq28X9yEMOSzhNolTkl Zq4LNMK02+u3CiNnwmG2izacJcQ7K5QAmi80b582i48U4Qpv+VYipW7UZBu5wJ+CAaM07zwBJ7UH5 zbo+m1n4gU49rm6JWKYQRDFK304+nrAIZWLXDM/awDlWefQwXEwPOq4PSel3KbH/FeU/nlP3r0sjQ H9+dShE2r3qo0Mcu27Yl5pvDlNAyfE9M6HUq7Uklsik9N7dNdTDw6y5SeMraGT5DxLQ4lHqlpa9NL Nu+QVqiA==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1u528A-0000000A7rI-3Nuc; Wed, 16 Apr 2025 12:44:43 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id B10733003C4; Wed, 16 Apr 2025 14:44:42 +0200 (CEST) Date: Wed, 16 Apr 2025 14:44:42 +0200 From: Peter Zijlstra To: Rik van Riel Cc: Chris Mason , Pat Cody , 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, linux-kernel@vger.kernel.org, patcody@meta.com, kernel-team@meta.com, Breno Leitao Subject: Re: [PATCH] sched/fair: Add null pointer check to pick_next_entity() Message-ID: <20250416124442.GC6580@noisy.programming.kicks-ass.net> References: <20250320205310.779888-1-pat@patcody.io> <20250324115613.GD14944@noisy.programming.kicks-ass.net> <7B2CFC16-1ADE-4565-B555-7525A50494C2@surriel.com> <20250402082221.GT5880@noisy.programming.kicks-ass.net> <20250415080235.GK5600@noisy.programming.kicks-ass.net> 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: <20250415080235.GK5600@noisy.programming.kicks-ass.net> On Tue, Apr 15, 2025 at 10:02:35AM +0200, Peter Zijlstra wrote: > On Mon, Apr 14, 2025 at 03:57:42PM -0400, Rik van Riel wrote: > > On Wed, 2025-04-02 at 10:22 +0200, Peter Zijlstra wrote: > > > > > > Please confirm what the reason for overflow is. > > > > > Running a large enough sample size has its benefits. > > > > We have hit 3 out of the 4 warnings below. > > > > The only one we did not hit is the cfs_rq->avg_load != avg_load > > warning. > > Fair enough, that one really isn't hard. > > > Most of the time we seem to hit the warnings from the > > code that removes tasks from the runqueue, > > *blink*.. Which warning is getting hit on removal? The avg_vruntime mismatch? Also, which removal path? schedule()'s block path, or migration like?