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 B74FE2FE59F; Mon, 13 Oct 2025 20:33:57 +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=1760387637; cv=none; b=kUUBIIuS/Spx6s87BvpCN93GbFWWxEcJ3ej+/gJ5emxS5RF3Kc4Tclw/lEo+KhElzc7nIdtvK+XbIolU2rQ4pp9XUsqBfLMyhOWXPl/8CTMc+WUs315JnkKnQ5b2thDqF8gjc38u4lSpdKw7PXov8lz6h4ZXR97mBohVvy0j+6g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760387637; c=relaxed/simple; bh=9w9KiM/XU5k7xFjzwkTNeoZAiAzOP0fQ9W37e2QyvME=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RF0nCvZt6JdkOcrZn0rDHg0Ub4pvCBfuCyijxC22cuTsNnw5pmDgGm6Ob+crfWXjGcBUSX2u9eTpWHKMqMH2EllyCa3/l8eNF/j9BPPzIwY39v9Q3zkiemDHKsQ/h3sR9X4W0sKZ0PgCJ+5P0eVm2hoJfisjkBSNi+7E6tEGfRQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fmNLj/57; 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="fmNLj/57" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B6A27C4CEF8; Mon, 13 Oct 2025 20:33:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760387637; bh=9w9KiM/XU5k7xFjzwkTNeoZAiAzOP0fQ9W37e2QyvME=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fmNLj/575P8R9C/Tos8QKO8qINbfYPqKweF8y9NhDYbJaZ+5jadfKFAc+rLxgfUup dUukeeCFad56TOrldk6Pyv5FB7Yib5oAFO6Oh+GpsoH5YTMif3zLX9QI3nrys+9Qxu YI6y7FSDOQhvhl/BwxSZQGkjCvTwSoxUK9shUsKldgjOfh/6u/XmAYh/vLJa/pm+ad +M/kiyWLN2KLfgpcqgBOzNf6g2Jz30nfxJo6oZKx2ju0jpStVAdF+RHNcTBckgDvg/ NJOw2T6qEqqICHSulF65mxm17kqfi/WfNxN+jo8ytmR8ZcpKkI/8i0v1+N8PdJ3EVO Z/RzqZx4g8l7Q== 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 15/33] sched/isolation: Flush vmstat workqueues on cpuset isolated partition change Date: Mon, 13 Oct 2025 22:31:28 +0200 Message-ID: <20251013203146.10162-16-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 HK_TYPE_DOMAIN housekeeping cpumask is now modifyable 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 c287998908bf..a81aa5635b47 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 9ec365dea921..5cd3d98a2663 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -145,6 +145,7 @@ int housekeeping_update(struct cpumask *mask, enum hk_type type) synchronize_rcu(); mem_cgroup_flush_workqueue(); + vmstat_flush_workqueue(); kfree(old); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 8bfc0b4b133f..84525885a3de 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 7afb2981501f..506d3ca2e47f 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -2115,6 +2115,11 @@ 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; -- 2.51.0