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 C1745305063; Mon, 13 Oct 2025 20:33:09 +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=1760387589; cv=none; b=jPQEMCFNLzfkQTQl1ukYFx70jr0EEQmtk2THqszMUxF/mOvtpzWw5AKvbW/q+O47W3aiPWBtXrF5cNvUydmiCLhAPRCgmWJmukrb3e1TRSH2FE3Oo8v23kkEnstuSoUmiVpKetdwnUHATxwCgqT0l1dRjnEZpOrb5cMKGGQQgX4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760387589; c=relaxed/simple; bh=Zhiq4FAEYOOXwB2NcOIuEEVkIt25SGkU6jm55H4Ks4Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hgK9hNj69C/7fA2khk4pKHTKxyxvtHzYmwVgtHnFBFmP0kg/3k7+Gez4Ly4jBLpA54H0hYQxtajkS3iXQ+DukszYgm2pea9MzArxVm7Cp2/G94U2HNM3T004XsfZskF/Py1BQhc4ywYgwLDqQC8FjEBe3PZhgjqDVCZY7izcFFc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mvk2TRk/; 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="mvk2TRk/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DDB19C4CEF8; Mon, 13 Oct 2025 20:33:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760387589; bh=Zhiq4FAEYOOXwB2NcOIuEEVkIt25SGkU6jm55H4Ks4Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mvk2TRk/bZZDmvYyXjSpYAxJwwi/0/BeNYW/oH0NNdambWd5E4WhkKaxkC2XnXaxW cvQI6mZnNElgP3DiWGIvqFiUh2qwNYR6She+AIEB+7ET2ACWDZyMf0gvEyfqLjrTN7 n9uGzm5WcL0neq9dB3jTkqBbPEaZdFex/CXOy5wSF1uPegIF6Nn7fC9N7IMrOXHHrJ IOmF8CKgE9m1c5Uytlqa0/dxqolwmLTHo78Mr6tbW7UxWY3enyTlF/w25fPF2m15t6 EALCRcJz4/b6qwAHy1Fzt+Og3PkSds+SA+Q6/y0JeMPEINCV8R9rLAu+IkUCCjSKIJ UflEVdcEI22cg== 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 09/33] block: Protect against concurrent isolated cpuset change Date: Mon, 13 Oct 2025 22:31:22 +0200 Message-ID: <20251013203146.10162-10-frederic@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251013203146.10162-1-frederic@kernel.org> References: <20251013203146.10162-1-frederic@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The block subsystem prevents running the workqueue to isolated CPUs, including those defined by cpuset isolated partitions. Since HK_TYPE_DOMAIN will soon contain both and be subject to runtime modifications, synchronize against housekeeping using the relevant lock. For full support of cpuset changes, the block subsystem may need to propagate changes to isolated cpumask through the workqueue in the future. Signed-off-by: Frederic Weisbecker --- block/blk-mq.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 09f579414161..ed1b8b149a8f 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4240,12 +4240,16 @@ static void blk_mq_map_swqueue(struct request_queue *q) /* * Rule out isolated CPUs from hctx->cpumask to avoid - * running block kworker on isolated CPUs + * running block kworker on isolated CPUs. + * FIXME: cpuset should propagate further changes to isolated CPUs + * here. */ + rcu_read_lock(); for_each_cpu(cpu, hctx->cpumask) { if (cpu_is_isolated(cpu)) cpumask_clear_cpu(cpu, hctx->cpumask); } + rcu_read_unlock(); /* * Initialize batch roundrobin counts -- 2.51.0