From: Lai Jiangshan <jiangshanlai@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: Lai Jiangshan <laijs@linux.alibaba.com>,
Tejun Heo <tj@kernel.org>, Lai Jiangshan <jiangshanlai@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Valentin Schneider <valentin.schneider@arm.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>
Subject: [PATCH 03/10] workqueue: Manually break affinity on pool detachment
Date: Mon, 14 Dec 2020 23:54:50 +0800 [thread overview]
Message-ID: <20201214155457.3430-4-jiangshanlai@gmail.com> (raw)
In-Reply-To: <20201214155457.3430-1-jiangshanlai@gmail.com>
From: Lai Jiangshan <laijs@linux.alibaba.com>
Don't rely on the scheduler to force break affinity for us -- it will
stop doing that for per-cpu-kthreads.
Fixes: 06249738a41a ("workqueue: Manually break affinity on hotplug")
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
---
kernel/workqueue.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 1f5b8385c0cf..1f6cb83e0bc5 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1885,6 +1885,16 @@ static void worker_detach_from_pool(struct worker *worker)
if (list_empty(&pool->workers))
detach_completion = pool->detach_completion;
+
+ /*
+ * The cpus of pool->attrs->cpumask might all go offline after
+ * detachment, and the scheduler may not force break affinity
+ * for us, so we do it on our own and unbind this worker which
+ * can't be unbound by workqueue_offline_cpu() since it doesn't
+ * belong to any pool after it.
+ */
+ set_cpus_allowed_ptr(worker->task, cpu_possible_mask);
+
mutex_unlock(&wq_pool_attach_mutex);
/* clear leftover flags without pool->lock after it is detached */
--
2.19.1.6.gb485710b
next prev parent reply other threads:[~2020-12-14 14:56 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-14 15:54 [PATCH 00/10] workqueue: break affinity initiatively Lai Jiangshan
2020-12-14 15:54 ` [PATCH 01/10] workqueue: restore unbound_workers' cpumask correctly Lai Jiangshan
2020-12-14 15:54 ` [PATCH 02/10] workqueue: use cpu_possible_mask instead of cpu_active_mask to break affinity Lai Jiangshan
2020-12-14 17:25 ` Peter Zijlstra
2020-12-15 8:33 ` Lai Jiangshan
2020-12-15 8:40 ` Peter Zijlstra
2020-12-16 14:32 ` Tejun Heo
2020-12-14 15:54 ` Lai Jiangshan [this message]
2020-12-14 15:54 ` [PATCH 04/10] workqueue: don't set the worker's cpumask when kthread_bind_mask() Lai Jiangshan
2020-12-16 14:39 ` Tejun Heo
2020-12-14 15:54 ` [PATCH 05/10] workqueue: introduce wq_online_cpumask Lai Jiangshan
2020-12-14 15:54 ` [PATCH 06/10] workqueue: use wq_online_cpumask in restore_unbound_workers_cpumask() Lai Jiangshan
2020-12-14 15:54 ` [PATCH 07/10] workqueue: Manually break affinity on hotplug for unbound pool Lai Jiangshan
2020-12-16 14:50 ` Tejun Heo
2020-12-14 15:54 ` [PATCH 08/10] workqueue: reorganize workqueue_online_cpu() Lai Jiangshan
2020-12-14 15:54 ` [PATCH 09/10] workqueue: reorganize workqueue_offline_cpu() unbind_workers() Lai Jiangshan
2020-12-14 15:54 ` [PATCH 10/10] workqueue: Fix affinity of kworkers when attaching into pool Lai Jiangshan
2020-12-15 15:03 ` Valentin Schneider
2020-12-14 17:36 ` [PATCH 00/10] workqueue: break affinity initiatively Peter Zijlstra
2020-12-15 5:44 ` Lai Jiangshan
2020-12-15 7:50 ` Peter Zijlstra
2020-12-15 8:14 ` Lai Jiangshan
2020-12-15 8:49 ` Peter Zijlstra
2020-12-15 9:46 ` Lai Jiangshan
2020-12-16 14:30 ` Tejun Heo
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