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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: Sun, 25 Jan 2026 23:45:11 +0100 Message-ID: <20260125224541.50226-5-frederic@kernel.org> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20260125224541.50226-1-frederic@kernel.org> References: <20260125224541.50226-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam11 X-Stat-Signature: j44qwmgs1i4kikxkhyar69cz68b39c1f X-Rspam-User: X-Rspamd-Queue-Id: 4E32440002 X-HE-Tag: 1769381186-135872 X-HE-Meta: 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 tWpvanQY 60ZPICWyPa1cefptJMg4lqkxXBIkHbF/W8e2uqf0HQvzYrqUesmihsfERftAG+HuIqfGLu282FjywMf3y6qBF2rjNly+BPIWLSSgCeOUorhdzUfuEpEespNspxpDs1GYYcwKxyF4BjUtklyxsVjlSGEJEbqBeFoyQW+2cGbAkkhacAUzctXZvC3AAkdNHCC6JbxzKObgxDuKDzVMsDWH4BvPXRFU5YvrusI1a7OQ08HuYg8a9uxnpE4K4RsdQTEd4Yq/VsKF9ZPNz2rY= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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