From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=220.197.31.5 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793625423; b=nk0Jfd8iz5MWFDURgtIfKpCQFZuViFdK5LR9x9ML5Fec4bNgs7MfmRUVNpf7BW8bb2o0 Dd9huHVFGjDvbAzDnzawmQxLMY6gyltfhtPpiuft4DQUzmxGsqYpr22fHqD6OwtzzLupS EVQh/uIiLj7Uzg3SaXRHrl1czVvnt1CvYGF1NcgPcdXWP2kP9H8SI4UNFQmmYvusw39FF ZiQnpJOOBZXMPdvI4B8n0wmXBnQXrDdIzsi5JBDA+BDx3XM3RWdiQcLwnMiobAEiaRpAX hm5mb8UUrxL6kY9P7vTv2c0mH1BG5iDF7xIhpVEuYAIjIKqhA4RAczcZuBRxRgz9AYQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793625423; h=DMARC-Filter:DKIM-Signature:Received:From:To:Cc:Subject:Date: Message-ID:X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding:X-CM-TRANSID:X-Coremail-Antispam: X-CM-SenderInfo; bh=c4K+MMBYl+1PUnm7aaBqRIW+g/QRIro5Cl62LG9r3dE=; b=JrG06trmIL6OF1nWRlxAnQ6pjMBbmDf5h3jLBHyAvOuVwpT9dyl6aOFNOLELZBd0eU+p LkBhoa7uXU7+OVB7LbXppHATwDUd97OZa9A3af20rjm/Gha1xeECBgYBhjnfEDLL2/RzE 9ietok6F8mmmHHkuOp7yi8KidIrfLLQWANcScx94K6eiZ6H57Ax+ZcPB89JHzVJ9Vn4su 80sFrOYPwxAAHSDYxr4tC2+N7EfQnNqE0l5ZxlmTyRd45/GZ/4kKAnP9Lj0WEwNGOuHNN iZkVBaqa9a6qro6UdV4t2gKtpnJcTscK2ahxUbGKGHkh6UgtiUw/ussjS7/EPy0jY4A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass header.d=163.com header.i=@163.com header.a=rsa-sha256 header.s=s110527 header.b=FPrF9q1B; arc=none smtp.remote-ip=220.197.31.5 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 20556606A326 for ; Mon, 2 Nov 2026 13:17:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 20556606A326 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=163.com header.i=@163.com header.a=rsa-sha256 header.s=s110527 header.b=FPrF9q1B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=c4 K+MMBYl+1PUnm7aaBqRIW+g/QRIro5Cl62LG9r3dE=; b=FPrF9q1B/rlrPic5gw mk9SsLsK1RZYLLsS9JGUcJgiVfDy+INbYBWRBeO7p6lwrIuxqu9A4F0nYNL6De/c AX3z6D00Kt6oQ/3royyL6rJrwki0LSujd/VuY2kVl3ohBMtoiX5ykhbMIuXZIfpD fk4zqow6sFJ6AGYe4Nsn7AvSc= Received: from localhost.localdomain (unknown []) by gzga-smtp-mtada-g0-0 (Coremail) with SMTP id _____wD3HwTujOhqus+bEw--.23094S2; Mon, 02 Nov 2026 21:15:27 +0800 (CST) From: albin_yang@163.com To: kayracizmeci@gmail.com, peterz@infradead.org, kprateek.nayak@amd.com Cc: albin_yang@163.com, albinwyang@tencent.com, bsegall@google.com, chen.yu@linux.dev, dietmar.eggemann@arm.com, jstultz@google.com, juri.lelli@redhat.com, linux-kernel@vger.kernel.org, mgorman@suse.de, mingo@redhat.com, rostedt@goodmis.org, vincent.guittot@linaro.org, vschneid@redhat.com Subject: Re: [PATCH] sched/stats: Fix run_delay over-count for proxy-migrated blocked donors Date: Mon, 2 Nov 2026 21:15:25 +0800 Message-ID: <20261102131525.1099362-1-albin_yang@163.com> X-Mailer: git-send-email 2.43.7 In-Reply-To: References: X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:_____wD3HwTujOhqus+bEw--.23094S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7ZF1rJw1xuw48CF18Cw4rZrb_yoW8Xw1kpr 9xKr13Xr4kG34DJwn3Aw4UXryUGr4rJ3y5tF4rJry8C3s5AryIq34xKr1rW3s8CryfAr42 vF4ru3yxAFnFywUanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0JUNIDwUUUUU= X-CM-SenderInfo: pdoex0xb1d0wi6rwjhhfrp/xtbCzg8z1WrojO9RzgAA3Z On Sun, Nov 01, 2026, Kayra Cizmeci wrote: > IDK if you added the comment Peter asked for, if you didn't please > add it in the final patch :-). Yes -- I stripped them only for the email; the final patch keeps comments. > It's up to Peter. Tho, makes sense to me if the other issue exists on > older versions. It does -- I booted a v6.12.115 kernel and ran the same reproducer there, with and without the v4 patch already on the list: kernel run_delay delta hit rate ----------------------------- ----------------- -------- 6.12.115, unpatched 147.98 - 147.99 ms 8/20 6.12.115, + v4 (sched_delayed) 0.00 ms 0/100 v7.3+ master, unpatched 147.94 - 147.99 ms 5/20 v7.3+ master, + the diff 0.00 ms 0/100 Same setup in all four: DELAY_DEQUEUE on, two CPUs used -- worker and a competitor on CPU0, main on CPU1 -- and main migrates the sleeping worker with sched_setaffinity(). run_delay is schedstat field 2. The unpatched delta matches the worker's own t_wake - t_migrate (147.99 vs 148.00 ms) -- the whole sleep is charged. The reproducer self-checks (must reproduce unpatched) and run_delay still grows ~40 ms per round, so the counter is alive, not switched off. None of this needs proxy exec -- v6.12 does not have it at all, so the delayed dequeue over-count is fully independent of the proxy one. And p->is_blocked only exists from v7.2: the is_blocked version cannot even be built on 6.12, so with both folded into a single patch, v6.12.y to v7.1.y has no fix at all. The reproducer is plain userspace (no module); I can provide it if needed. Thanks, Wei Yang