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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 16/33] sched/isolation: Flush vmstat workqueues on cpuset isolated partition change Date: Sun, 25 Jan 2026 23:45:23 +0100 Message-ID: <20260125224541.50226-17-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: 6cifmfyoc96gw37i7knj37cp4j3ehzti X-Rspam-User: X-Rspamd-Queue-Id: 1B395180005 X-HE-Tag: 1769381282-100652 X-HE-Meta: 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 JCvUFnE6 Czzu45XFv7KmR7N2AnyJQf94NtywbBQ0Vlgqch2G66TvT6+mxsHgpHOFEw/MdBU+R17M/Vx1rM43v9CpCEc37HQXH2KOHn1K78uYdHicV5mVNpdsx4XpcweKf3+oyMLv6FZa2/FOFLFYsbJ1jYG2cCCv8u0+q8Os3PscefzVjdUgz2O+FUdsIbd8u2pWzFrC2E3QqMTvM+aLf2Dr2r388mVyMzWNFSlN6OsyA9Qj21HlwAGnxQNBOCrvLu9kJUkzp6PTfVFKwkqRlsbK+jQmwQlo0oVgdEy8M1KykWKZLh0MpJHS2fwzvAToAvQ== 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 is now modifiable at runtime. In order to synchronize against vmstat workqueue to make sure that no asynchronous vmstat work is still pending or executing on a newly made isolated CPU, the housekeeping susbsystem must flush the vmstat workqueues. This involves flushing the whole mm_percpu_wq workqueue, shared with LRU drain, introducing here a welcome side effect. Signed-off-by: Frederic Weisbecker --- include/linux/vmstat.h | 2 ++ kernel/sched/isolation.c | 1 + kernel/sched/sched.h | 1 + mm/vmstat.c | 5 +++++ 4 files changed, 9 insertions(+) diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h index 3398a345bda8..1909b945b3ea 100644 --- a/include/linux/vmstat.h +++ b/include/linux/vmstat.h @@ -303,6 +303,7 @@ int calculate_pressure_threshold(struct zone *zone); int calculate_normal_threshold(struct zone *zone); void set_pgdat_percpu_threshold(pg_data_t *pgdat, int (*calculate_pressure)(struct zone *)); +void vmstat_flush_workqueue(void); #else /* CONFIG_SMP */ /* @@ -403,6 +404,7 @@ static inline void __dec_node_page_state(struct page *page, static inline void refresh_zone_stat_thresholds(void) { } static inline void cpu_vm_stats_fold(int cpu) { } static inline void quiet_vmstat(void) { } +static inline void vmstat_flush_workqueue(void) { } static inline void drain_zonestat(struct zone *zone, struct per_cpu_zonestat *pzstats) { } diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index f4053ebf4027..160b3fcab209 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -145,6 +145,7 @@ int housekeeping_update(struct cpumask *isol_mask) synchronize_rcu(); mem_cgroup_flush_workqueue(); + vmstat_flush_workqueue(); kfree(old); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 65dfa48e54b7..2d0c408fca0b 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -68,6 +68,7 @@ #include #include #include +#include #include #include #include diff --git a/mm/vmstat.c b/mm/vmstat.c index ed19c0d42de6..d6e814c82952 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -2124,6 +2124,11 @@ static void vmstat_shepherd(struct work_struct *w); static DECLARE_DEFERRABLE_WORK(shepherd, vmstat_shepherd); +void vmstat_flush_workqueue(void) +{ + flush_workqueue(mm_percpu_wq); +} + static void vmstat_shepherd(struct work_struct *w) { int cpu; -- 2.51.1