[PATCH 02/10] workqueue: use cpu_possible_mask instead of cpu_active_mask to break affinity

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 02/10] workqueue: use cpu_possible_mask instead of cpu_active_mask to break affinity
Date: Mon, 14 Dec 2020 23:54:49 +0800	[thread overview]
Message-ID: <20201214155457.3430-3-jiangshanlai@gmail.com> (raw)
In-Reply-To: <20201214155457.3430-1-jiangshanlai@gmail.com>

From: Lai Jiangshan <laijs@linux.alibaba.com>

There might be other CPU online. The workers losing binding on its CPU
should have chance to work on those later onlined CPUs.

Fixes: 06249738a41a ("workqueue: Manually break affinity on hotplug")
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
---
 kernel/workqueue.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index aba71ab359dd..1f5b8385c0cf 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -4909,8 +4909,9 @@ static void unbind_workers(int cpu)
 
 		raw_spin_unlock_irq(&pool->lock);
 
+		/* don't rely on the scheduler to force break affinity for us. */
 		for_each_pool_worker(worker, pool)
-			WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, cpu_active_mask) < 0);
+			WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, cpu_possible_mask) < 0);
 
 		mutex_unlock(&wq_pool_attach_mutex);
 
-- 
2.19.1.6.gb485710b

