From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E43A02BD5A7; Wed, 5 Nov 2025 21:04:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762376674; cv=none; b=hV9PZb25Q2Docpv3S23S7B99J8Xdh6Of0N0BPw0u633MFLXXllz68OOUSx5LahX+7p6R2mML1CNgybWeZdLHyGuVycodO9fGIDPyNjXV0KilFJWUFne6G7ZEm78ublVsFxmRSGxdD6iiXebOAXPOT/SNZ6JB+mMQrZXtiWSEkAA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762376674; c=relaxed/simple; bh=ApQa5R07ipGBiVCyA3EgObV++ftyWFoj/ra3rzP5dCY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=usccpBdhZghUIgDAku7z92DqJZqzJPYnQHuazzV6+DqXIZGBnbtgXPVeaXnaVzeI2022LCH1O3Uz0J/N9tYYqQ9hth8GVtOFfcpWyxpwOMo6Ly4Yz9qg6B/2WZ3u9as8/c6ZkcUkPRua7+oF6bAskAncMlljZKZaanykd8EtyYo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cyGGAVyE; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cyGGAVyE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1FFC7C4AF09; Wed, 5 Nov 2025 21:04:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762376673; bh=ApQa5R07ipGBiVCyA3EgObV++ftyWFoj/ra3rzP5dCY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cyGGAVyEEtnTJleIGvRPvdX/Cc6KEP2KDLlXtGtmXgRrPqu8Hr6k4dV2PS4NZXG/b 0TuJ9Xv9ZVXQWSh2Q5s5CnahVU/19PTlWf5bvziWhR6igHAhOvKcyNWxStp0IREsuQ dCvjHLJNUd14dOSieLUuFACfi9H0I3xpfHEEvQVGyxubT+iCI4qTrf+SBosWgX9JwY q8wUhQKNtbk77Gb5lvCUyYfdwPpF6f8ZJlnEwEOgiTX7YW4gUFPYiJIdvr5mvwbwxf m8/DbHKO9hBpJpzZlv5oT+4ck92P+ii+pCIyA06mlA6F7sTvBrnc5dZH921cfMjKM3 ISpiuGCwxLlCw== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Andrew Morton , Bjorn Helgaas , Catalin Marinas , Danilo Krummrich , "David S . Miller" , Eric Dumazet , Gabriele Monaco , Greg Kroah-Hartman , Ingo Molnar , Jakub Kicinski , Jens Axboe , Johannes Weiner , Lai Jiangshan , Marco Crivellari , Michal Hocko , Muchun Song , Paolo Abeni , Peter Zijlstra , Phil Auld , "Rafael J . Wysocki" , Roman Gushchin , Shakeel Butt , Simon Horman , Tejun Heo , Thomas Gleixner , Vlastimil Babka , Waiman Long , Will Deacon , cgroups@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-block@vger.kernel.org, linux-mm@kvack.org, linux-pci@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH 04/31] mm: vmstat: Prepare to protect against concurrent isolated cpuset change Date: Wed, 5 Nov 2025 22:03:20 +0100 Message-ID: <20251105210348.35256-5-frederic@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251105210348.35256-1-frederic@kernel.org> References: <20251105210348.35256-1-frederic@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The HK_TYPE_DOMAIN housekeeping cpumask will soon be made modifiable at runtime. In order to synchronize against vmstat workqueue to make sure that no asynchronous vmstat work is pending or executing on a newly made isolated CPU, target and queue a vmstat work under the same RCU read side critical section. Whenever housekeeping will update the HK_TYPE_DOMAIN cpumask, a vmstat workqueue flush will also be issued in a further change to make sure that no work remains pending after a CPU has been made isolated. Signed-off-by: Frederic Weisbecker --- mm/vmstat.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/mm/vmstat.c b/mm/vmstat.c index bb09c032eecf..7afb2981501f 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -2135,11 +2135,13 @@ static void vmstat_shepherd(struct work_struct *w) * infrastructure ever noticing. Skip regular flushing from vmstat_shepherd * for all isolated CPUs to avoid interference with the isolated workload. */ - if (cpu_is_isolated(cpu)) - continue; + scoped_guard(rcu) { + if (cpu_is_isolated(cpu)) + continue; - if (!delayed_work_pending(dw) && need_update(cpu)) - queue_delayed_work_on(cpu, mm_percpu_wq, dw, 0); + if (!delayed_work_pending(dw) && need_update(cpu)) + queue_delayed_work_on(cpu, mm_percpu_wq, dw, 0); + } cond_resched(); } -- 2.51.0