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From: Oleg Nesterov <oleg@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>, Tejun Heo <tj@kernel.org>
Cc: paulmck@linux.vnet.ibm.com, mingo@redhat.com, der.herr@hofr.at,
	dave@stgolabs.net, riel@redhat.com, viro@ZenIV.linux.org.uk,
	torvalds@linux-foundation.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/5] stop_machine: don't do for_each_cpu() twice in queue_stop_cpus_work()
Date: Tue, 30 Jun 2015 03:29:48 +0200	[thread overview]
Message-ID: <20150630012948.GA23927@redhat.com> (raw)
In-Reply-To: <20150630012931.GA23904@redhat.com>

queue_stop_cpus_work() can do everything in one for_each_cpu() loop.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 kernel/stop_machine.c |   17 +++++++----------
 1 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 6e677b0..6212208 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -303,22 +303,19 @@ static void queue_stop_cpus_work(const struct cpumask *cpumask,
 	struct cpu_stop_work *work;
 	unsigned int cpu;
 
-	/* initialize works and done */
-	for_each_cpu(cpu, cpumask) {
-		work = &per_cpu(cpu_stopper.stop_work, cpu);
-		work->fn = fn;
-		work->arg = arg;
-		work->done = done;
-	}
-
 	/*
 	 * Disable preemption while queueing to avoid getting
 	 * preempted by a stopper which might wait for other stoppers
 	 * to enter @fn which can lead to deadlock.
 	 */
 	lg_global_lock(&stop_cpus_lock);
-	for_each_cpu(cpu, cpumask)
-		cpu_stop_queue_work(cpu, &per_cpu(cpu_stopper.stop_work, cpu));
+	for_each_cpu(cpu, cpumask) {
+		work = &per_cpu(cpu_stopper.stop_work, cpu);
+		work->fn = fn;
+		work->arg = arg;
+		work->done = done;
+		cpu_stop_queue_work(cpu, work);
+	}
 	lg_global_unlock(&stop_cpus_lock);
 }
 
-- 
1.5.5.1


  parent reply	other threads:[~2015-06-30  1:31 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-30  1:29 [PATCH 0/5] stop_machine: cleanups and fix Oleg Nesterov
2015-06-30  1:29 ` [PATCH 1/5] stop_machine: move cpu_stopper_task and stop_cpus_work into struct cpu_stopper Oleg Nesterov
2015-08-03 17:08   ` [tip:sched/core] stop_machine: Move 'cpu_stopper_task' and ' stop_cpus_work' into 'struct cpu_stopper' tip-bot for Oleg Nesterov
2015-06-30  1:29 ` Oleg Nesterov [this message]
2015-08-03 17:09   ` [tip:sched/core] stop_machine: Don't do for_each_cpu() twice in queue_stop_cpus_work() tip-bot for Oleg Nesterov
2015-06-30  1:29 ` [PATCH 3/5] stop_machine: unexport __stop_machine() Oleg Nesterov
2015-08-03 17:09   ` [tip:sched/core] stop_machine: Unexport __stop_machine() tip-bot for Oleg Nesterov
2015-06-30  1:29 ` [PATCH 4/5] stop_machine: use cpu_stop_fn_t where possible Oleg Nesterov
2015-06-30 14:28   ` Peter Zijlstra
2015-08-03 17:09   ` [tip:sched/core] stop_machine: Use 'cpu_stop_fn_t' " tip-bot for Oleg Nesterov
2015-06-30  1:29 ` [PATCH 5/5] stop_machine: cpu_stop_park() should remove cpu_stop_work's from list Oleg Nesterov
2015-08-03 17:10   ` [tip:sched/core] stop_machine: Remove cpu_stop_work' s from list in cpu_stop_park() tip-bot for Oleg Nesterov
2015-06-30 12:52 ` [PATCH 0/5] stop_machine: cleanups and fix Oleg Nesterov
2015-07-01 19:22   ` Oleg Nesterov
2015-07-01 19:23 ` [PATCH 6/5] stop_machine: kill stop_cpus_lock and lg_double_lock/unlock() Oleg Nesterov

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