From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA246EEB57A for ; Sat, 9 Sep 2023 00:51:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245645AbjIIAvH (ORCPT ); Fri, 8 Sep 2023 20:51:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239783AbjIIAvG (ORCPT ); Fri, 8 Sep 2023 20:51:06 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 029EE44B7; Fri, 8 Sep 2023 17:41:30 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BB707C116AE; Sat, 9 Sep 2023 00:41:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694220072; bh=qTGrG/4JaeqgSoo84qlJqZ3mukGoHBWMkFM49gwhkVM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AttgGqgRdDlNMNEDljOcw8QnFAAqB/IVFXE6wHx25+jZKu97aitwL37gbq8fPoeDN 1hazpUu12BjG3020HH4+ThSCIfxv+fZwBxxSIMhuwK74FG7tov34CPU1EqpRIsemu/ FVA/HdTi0Uu5rNza1i1U/2Nhqd8vKJzfLIeURCbHyzHkAb1wk7DV92JlUIbcp5Apta /Kf7qvqwNtMChpjqUbmsyh+nMablZOlRgIrng4XK9yOMl3dgbl1BKXD4/C56avpWYa IXdcupZcUSp88pKT+gRCufCF7HpmzmJQdhEgxhk1J3uHuk+ZrjfJ6vhS2NQK2wCndd GbCkBj8wrZjTg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tejun Heo , Sasha Levin Subject: [PATCH AUTOSEL 4.19 12/14] workqueue: Call wq_update_unbound_numa() on all CPUs in NUMA node on CPU hotplug Date: Fri, 8 Sep 2023 20:40:43 -0400 Message-Id: <20230909004045.3581014-12-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230909004045.3581014-1-sashal@kernel.org> References: <20230909004045.3581014-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 4.19.294 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tejun Heo [ Upstream commit 4cbfd3de737b9d00544ff0f673cb75fc37bffb6a ] When a CPU went online or offline, wq_update_unbound_numa() was called only on the CPU which was going up or down. This works fine because all CPUs on the same NUMA node share the same pool_workqueue slot - one CPU updating it updates it for everyone in the node. However, future changes will make each CPU use a separate pool_workqueue even when they're sharing the same worker_pool, which requires updating pool_workqueue's for all CPUs which may be sharing the same pool_workqueue on hotplug. To accommodate the planned changes, this patch updates workqueue_on/offline_cpu() so that they call wq_update_unbound_numa() for all CPUs sharing the same NUMA node as the CPU going up or down. In the current code, the second+ calls would be noops and there shouldn't be any behavior changes. * As wq_update_unbound_numa() is now called on multiple CPUs per each hotplug event, @cpu is renamed to @hotplug_cpu and another @cpu argument is added. The former indicates the CPU being hot[un]plugged and the latter the CPU whose pool_workqueue is being updated. * In wq_update_unbound_numa(), cpu_off is renamed to off_cpu for consistency with the new @hotplug_cpu. Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin --- kernel/workqueue.c | 34 +++++++++++++++++++++++++--------- 1 file changed, 25 insertions(+), 9 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 5533206cb6f48..c994b06f60f2f 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -3907,7 +3907,8 @@ EXPORT_SYMBOL_GPL(apply_workqueue_attrs); /** * wq_update_unbound_numa - update NUMA affinity of a wq for CPU hot[un]plug * @wq: the target workqueue - * @cpu: the CPU coming up or going down + * @cpu: the CPU to update pool association for + * @hotplug_cpu: the CPU coming up or going down * @online: whether @cpu is coming up or going down * * This function is to be called from %CPU_DOWN_PREPARE, %CPU_ONLINE and @@ -3927,10 +3928,10 @@ EXPORT_SYMBOL_GPL(apply_workqueue_attrs); * CPU_DOWN_PREPARE. */ static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu, - bool online) + int hotplug_cpu, bool online) { int node = cpu_to_node(cpu); - int cpu_off = online ? -1 : cpu; + int off_cpu = online ? -1 : hotplug_cpu; struct pool_workqueue *old_pwq = NULL, *pwq; struct workqueue_attrs *target_attrs; cpumask_t *cpumask; @@ -3958,7 +3959,7 @@ static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu, * and create a new one if they don't match. If the target cpumask * equals the default pwq's, the default pwq should be used. */ - if (wq_calc_node_cpumask(wq->dfl_pwq->pool->attrs, node, cpu_off, cpumask)) { + if (wq_calc_node_cpumask(wq->dfl_pwq->pool->attrs, node, off_cpu, cpumask)) { if (cpumask_equal(cpumask, pwq->pool->attrs->cpumask)) return; } else { @@ -4876,8 +4877,15 @@ int workqueue_online_cpu(unsigned int cpu) } /* update NUMA affinity of unbound workqueues */ - list_for_each_entry(wq, &workqueues, list) - wq_update_unbound_numa(wq, cpu, true); + list_for_each_entry(wq, &workqueues, list) { + int tcpu; + + for_each_possible_cpu(tcpu) { + if (cpu_to_node(tcpu) == cpu_to_node(cpu)) { + wq_update_unbound_numa(wq, tcpu, cpu, true); + } + } + } mutex_unlock(&wq_pool_mutex); return 0; @@ -4895,8 +4903,15 @@ int workqueue_offline_cpu(unsigned int cpu) /* update NUMA affinity of unbound workqueues */ mutex_lock(&wq_pool_mutex); - list_for_each_entry(wq, &workqueues, list) - wq_update_unbound_numa(wq, cpu, false); + list_for_each_entry(wq, &workqueues, list) { + int tcpu; + + for_each_possible_cpu(tcpu) { + if (cpu_to_node(tcpu) == cpu_to_node(cpu)) { + wq_update_unbound_numa(wq, tcpu, cpu, false); + } + } + } mutex_unlock(&wq_pool_mutex); return 0; @@ -5843,7 +5858,8 @@ int __init workqueue_init(void) } list_for_each_entry(wq, &workqueues, list) { - wq_update_unbound_numa(wq, smp_processor_id(), true); + wq_update_unbound_numa(wq, smp_processor_id(), smp_processor_id(), + true); WARN(init_rescuer(wq), "workqueue: failed to create early rescuer for %s", wq->name); -- 2.40.1