From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e31.co.us.ibm.com (e31.co.us.ibm.com [32.97.110.149]) (using TLSv1.2 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3rPFVH5pl3zDqHQ for ; Wed, 8 Jun 2016 01:14:47 +1000 (AEST) Received: from localhost by e31.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 7 Jun 2016 09:14:42 -0600 From: "Gautham R. Shenoy" To: Peter Zijlstra , Thomas Gleixner , Tejun Heo , Michael Ellerman , Abdul Haleem , Aneesh Kumar Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, "Gautham R. Shenoy" Subject: [PATCH 1/2] workqueue: Move wq_update_unbound_numa() to the beginning of CPU_ONLINE Date: Tue, 7 Jun 2016 20:44:02 +0530 Message-Id: <6b3c7059ec5d2d6157d23d619e4507692a42a5bd.1465311052.git.ego@linux.vnet.ibm.com> In-Reply-To: References: <5756BE20.3040208@linux.vnet.ibm.com> In-Reply-To: References: List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Currently in the CPU_ONLINE workqueue handler, the restore_unbound_workers_cpumask() will never call set_cpus_allowed_ptr() for a newly created unbound worker thread. This is because the function which creates a new unbound worker thread when the first CPU in the node comes online [wq_update_unbound_numa()] is invoked after the call to restore_unbound_workers_cpumask(). Thus the affinity is never set for this worker thread when the first CPU in the node comes online. Furthermore, due to an optimization in restore_unbound_workers_cpumask(), set_cpus_allowed_ptr() is not called when subsequent CPUs in the node come online since it assumes that the affinity would have been set when the first CPU has come online. This patch fixes this issue by invoking wq_update_unbound_numa() before the calling restore_unbound_workers_cpumask(). Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tejun Heo Cc: Michael Ellerman Signed-off-by: Gautham R. Shenoy --- kernel/workqueue.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index e1c0e99..e412794 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -4638,6 +4638,10 @@ static int workqueue_cpu_up_callback(struct notifier_block *nfb, case CPU_ONLINE: mutex_lock(&wq_pool_mutex); + /* update NUMA affinity of unbound workqueues */ + list_for_each_entry(wq, &workqueues, list) + wq_update_unbound_numa(wq, cpu, true); + for_each_pool(pool, pi) { mutex_lock(&pool->attach_mutex); @@ -4649,10 +4653,6 @@ static int workqueue_cpu_up_callback(struct notifier_block *nfb, mutex_unlock(&pool->attach_mutex); } - /* update NUMA affinity of unbound workqueues */ - list_for_each_entry(wq, &workqueues, list) - wq_update_unbound_numa(wq, cpu, true); - mutex_unlock(&wq_pool_mutex); break; } -- 1.9.3