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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: Thu, 1 Jan 2026 23:13:29 +0100 Message-ID: <20260101221359.22298-5-frederic@kernel.org> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20260101221359.22298-1-frederic@kernel.org> References: <20260101221359.22298-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 7593220003 X-Stat-Signature: j8jebk865hitauuujajtbmtj5wryqm7h X-HE-Tag: 1767305686-177878 X-HE-Meta: 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 p/lph/Fo mwy7w/0MCINgD6ejB6eAUB5jGQkoGYc2hXNo5Tefs0UtDZ2ItCrwhR8tcQWi5zAm6vaFqU93QLedd/mbllxns6+yBzuwhyHjcqfP9C+cilC98a3kQIpu/kshNx5OLlmLCfK9IsNexqoMzfpkQRQ+S6XwlJTAb+Gpj5f2mLOIlYu0FEfaUIiqgFSdcTtGuKUe2+pgy9HfNdaBjNdQdxzPgdutMtn3LgYb5NUGvHy5EfUerkj31rrAYkP0cdjBEYzfoBapY9eTCBlJrTys= 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