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 76D0C32FA38; Wed, 24 Dec 2025 13:46:07 +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=1766583967; cv=none; b=A/3T/YQDNJH3oPYve4xy12WFUtEdfmuaUzQ29jdOneeRB/hCTB3C6+yrBL5RV8ZzYx1XnFSE/DI4yjX9pdgiratz4NolJyaFZ+lWFPeWO+gJfbGuhEl/kIBsDNLokSUqjRRYP2uI80ifFI/FdQu4B0XYch58/P1lgomnImj+hOY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766583967; c=relaxed/simple; bh=gBHkj0y4jQxeMV2qzbEciSScfrXq1yZennkNx/2Itiw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=r5uJGRXP4353so5+YPRFJxGryN/cmycpuRE85ZGVWX3gJXicnBBQbHWxRWRBPIKMyYsP5NJDO/ZyhxpxGiTRjUY2IeHzD4ERSk04hNceee7fLrd2Z/2XUT7DPj3cCOUsfwO61qsiOTFD8lJoUBBjUl6Mvh56F2vInqyxwEWrD+k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=evUDJBdS; 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="evUDJBdS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 17469C4CEFB; Wed, 24 Dec 2025 13:45:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1766583967; bh=gBHkj0y4jQxeMV2qzbEciSScfrXq1yZennkNx/2Itiw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=evUDJBdSDfWTSettVdnrBmEWuArMIbMTOqJKbYP3p9elzByKiCT7UXNvzG/XZrMOj BA9LFmcovhu6mXlJ60rnaVM8FmAA7/x9xbspH5+9InXVw2X7s7ugla6lGwjCX4FfcJ JC2v9n+hQov6cJNLR2BVz5QIH/VJCx1TFceMK/mt3xc7TDmk+CCAqBDdJv15d5KIXB T+BcmVnTwkiL+nUwRVs3a/Omke+zPfDhsJkfrmITuRWexeqomKaWoRJcx5EmZh0yk5 +F3C3hJ0nXTfy0QBGT1xSH3YFrqmpt5fEheIK3FTUGtSRTNE3hajKZX++/AoBioaWf tH5bzsMsmAY+w== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Andrew Morton , Bjorn Helgaas , Catalin Marinas , Chen Ridong , 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 04/33] mm: vmstat: Prepare to protect against concurrent isolated cpuset change Date: Wed, 24 Dec 2025 14:44:51 +0100 Message-ID: <20251224134520.33231-5-frederic@kernel.org> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20251224134520.33231-1-frederic@kernel.org> References: <20251224134520.33231-1-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 65de88cdf40e..ed19c0d42de6 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -2144,11 +2144,13 @@ 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(); } -- 2.51.1