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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 04/31] 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> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 58465A000B X-Stat-Signature: 1edx8x69r64oj7cmg31w78a6s3sqcgka X-Rspam-User: X-HE-Tag: 1762376674-257607 X-HE-Meta: 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 71GF/jUl 0ChXG555cDE36vrMLkUbpmilgFfVIjJdYKkkZRqs5V9QVrUDm94voszu+c11byUs8b4veTZbA+USFy6QIVW/Zvpa0ZiYfxxJamnNuIWLRnLw1nMOK30KjS3pfy4PwKuB9TS67rwkR78jWZVL9EZO8wEpF3KsJwLzz3fzr1VHmccU9oZdTrYP3jX/pzpc9lvcH1iptsVYCFvMvZhYNAE8qdgbK54eCjbV0niQoDlOmyV6fPWAhMBTmmoWExrBjz4x6+anhRBoHQU78OTs= 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 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