From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out28-76.mail.aliyun.com (out28-76.mail.aliyun.com [115.124.28.76]) (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 333CC24DCF9 for ; Thu, 15 Oct 2026 01:40:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.28.76 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792028417; cv=none; b=WK4uWBSj4bfYOcSPTNL+8hA4Nh5y7FG8qG4zws3ddNcL+IchpBd86GewvySWO7GZlgzJPCPgTppEKvTAREufJuIwvux7NbGl/zkTAiBvWVhQHDXNGItg5IseDMW1j3Yey+lgqrjBBRnYGYAln6F3nDFn9wsk80LmgD0mxopgpPY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792028417; c=relaxed/simple; bh=H+v/gqnjWQ3O7ct/IIm0+uSIkR+hWzXeTbgrHmFdb/0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pqDYsFMkQagPcqG03h01Xolpi+p4/xFbNR5f+Jt7cQUS98I/mp6sAQiWWZ+p+Pt/Dy87m5OWLVYPVdiQeBOECi73TNcbatSx38i9OAbMJ7ftqIs5yZ8i5+GPmUItWqNuaQLFV36fio8TKEa8omxOFUwMFFxxjsaHkwJfMhW8l5I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=xiaopeng.com; spf=pass smtp.mailfrom=xiaopeng.com; dkim=pass (1024-bit key) header.d=xiaopeng.com header.i=@xiaopeng.com header.b=PfT12lda; arc=none smtp.client-ip=115.124.28.76 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=xiaopeng.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=xiaopeng.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=xiaopeng.com header.i=@xiaopeng.com header.b="PfT12lda" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=xiaopeng.com; s=default; t=1792028407; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=H+v/gqnjWQ3O7ct/IIm0+uSIkR+hWzXeTbgrHmFdb/0=; b=PfT12ldaoZmCUxV36k9Zzs2dQ7x4Ps8jKg8dTpDL1uy/DwcokoeKBIjcFJneeIuFNeksc7peXgl1aVGZUKm7T99AaPfVakalNfY2D3zunq8rWkI8XOdxhhafMjai60XINL7HvQrwiNPh9PFFerydIOtdh+ZgAVNyGFTNrj0vNY4= X-Alimail-AntiSpam:AC=CONTINUE;BC=0.1178455|-1;CH=green;DM=|CONTINUE|false|;DS=CONTINUE|ham_enroll_verification|0.192236-0.0012412-0.806522;FP=12588089935714567190|0|0|0|0|-1|-1|-1;HT=maildocker-contentspam033040074035;MF=wangqk1@xiaopeng.com;NM=1;PH=DS;RN=10;RT=10;SR=0;TI=SMTPD_---.je7cEbj_1792028406; Received: from DESKTOP-EL1SUEF.xiaopeng.local(mailfrom:wangqk1@xiaopeng.com fp:SMTPD_---.je7cEbj_1792028406 cluster:ay29) by smtp.aliyun-inc.com; Thu, 15 Oct 2026 09:40:06 +0800 From: wangqk1 To: peterz@infradead.org Cc: linux-kernel@vger.kernel.org, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, bigeasy@linutronix.de, clrkwllms@kernel.org, rostedt@goodmis.org, linux-rt-devel@lists.linux.dev, xiedl3@xiaopeng.com Subject: Re: [RFC 1/1] sched/rt: Avoid RTO push to stopped CPUs during shutdown Date: Thu, 15 Oct 2026 09:40:05 +0800 Message-ID: <20261015014005.8885-1-wangqk1@xiaopeng.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261013120302.GJ2009045@noisy.programming.kicks-ass.net> References: <20261013120302.GJ2009045@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-Transfer-Encoding: 8bit On Tue, Oct 13, 2026 at 02:03:02PM +0200, Peter Zijlstra wrote: > This is horrific; lets not do this. The bug really is at the place where > you randomly and without warning take CPUs down. We're not adding random > hacks for things like that. Understood, thanks for the quick feedback. I am dropping this patch. One note on the trigger: this was seen on the normal poweroff path, not on panic or crash. On arm64, machine_power_off() calls smp_send_stop() before do_kernel_power_off(), so every orderly shutdown stops secondary CPUs without hotplug teardown, and a CPU still running the rto push irq_work can then pick a stale rto_mask bit. I agree the fix belongs in the path that takes the CPUs down, and that path will need to account for the rto overload state. If I find a viable way to do that, I will bring it up again. Happy to test or review anything in that area. Thanks, wangqk1