From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-244106.protonmail.ch (mail-244106.protonmail.ch [109.224.244.106]) (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 E37CE1D5AC0 for ; Fri, 21 Mar 2025 17:52:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=109.224.244.106 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742579559; cv=none; b=iM0+dYGWiqerobwDC9YB6E9bwpzTPAY6sMTCSzVtIciEt+VE3AFaJDdTCB+aqI9jqsI3WIE6fp4nfZqvh4RP3prpUe58h6DV8wECf+8TwgO7lxHi01nxTPBNEDB7M7UH+8lbmtW7o4oqMBs+COQHMN1kg8kKLORoCEKi0v1iDsE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742579559; c=relaxed/simple; bh=3KbwbiIdZD9SwPO5/Ys1Ipv2htc083kqYRR4qOWVVyY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Zf38OnKBdVVyfTVgqNVxpQhmUvpoqd1UAY6SnAQOsCdAxsu4o3YGDHHWYilE/+vkm7fBKLdq8otgjqj+otOOMSC38+xGFAVPZqiSysIcNnMCn2AIqpbpikpH2On9pIbz5i/3zX2m33YDyr6mQDk9js5riKWeT3ykfmqQPv+Qweg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=patcody.io; spf=pass smtp.mailfrom=patcody.io; dkim=pass (2048-bit key) header.d=patcody.io header.i=@patcody.io header.b=rWmuvsVa; arc=none smtp.client-ip=109.224.244.106 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=patcody.io Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=patcody.io Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=patcody.io header.i=@patcody.io header.b="rWmuvsVa" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=patcody.io; s=protonmail; t=1742579553; x=1742838753; bh=ZFYA/cCQuoMCq2M/VnoisL8CaGvvio8pJRHM3dKEtuU=; h=Date:From:To:Cc:Subject:Message-ID:References:In-Reply-To:From:To: Cc:Date:Subject:Reply-To:Feedback-ID:Message-ID:BIMI-Selector: List-Unsubscribe:List-Unsubscribe-Post; b=rWmuvsVaxRl8KnWGiWrSB96AwDf9LpIrCYLbb/o7HkRJ2JzPDWPf+kwQt50rNNMXR 19zu4gTUqJKU21r63k5C6oxaiKB+kISPaud5/4J0nuH41X/OIi2166areV3zxgYojW qHp0AbMOoqazmxPb1EJCx9s9h4xVxXms7DtNLcGeWURFnS+8gnrw2Z94uPYTmp//6R wHORoctjh4diZDuxsEZXTbsPW/TKhpp0NE3ZIqoYap1zoMdzzUJjk61fkkSOP+tdCF L7jxVcbjaosjPorH4xClsvuVBf+VHfYHOdiWA6ETNKWYzuk/7tKbBnAKgzRTp4A3l7 388A3bUKXwHQw== X-Pm-Submission-Id: 4ZK95B2lg8zNx Date: Fri, 21 Mar 2025 10:52:29 -0700 From: Pat Cody To: Christian Loehle Cc: mingo@redhat.com, peterz@infradead.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, linux-kernel@vger.kernel.org, riel@surriel.com, patcody@meta.com, kernel-team@meta.com, stable@vger.kernel.org Subject: Re: [PATCH] sched/fair: Add null pointer check to pick_next_entity() Message-ID: References: <20250320205310.779888-1-pat@patcody.io> <72cb8df7-42e7-4266-b014-7d43796b14d8@arm.com> Precedence: bulk X-Mailing-List: stable@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: <72cb8df7-42e7-4266-b014-7d43796b14d8@arm.com> On Thu, Mar 20, 2025 at 10:42:44PM +0000, Christian Loehle wrote: > Did this happen on mainline? Any chance it's reproducible? We have the following back-ported on top of 6.13: sched/fair: Adhere to place_entity() constraints (not upstreamed, see https://lore.kernel.org/all/20250207111141.GD7145@noisy.programming.kicks-ass.net/) a430d99e3490 sched/fair: Fix value reported by hot tasks pulled in /proc/schedstat 2a77e4be12cb sched/fair: Untangle NEXT_BUDDY and pick_next_task() We don't have a repro, but the crash in pick_task_fair happens more often than MCE crashes with our limited deployment of 6.13.