All of lore.kernel.org
 help / color / mirror / Atom feed
From: Oleg Nesterov <oleg@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>,
	paulmck@linux.vnet.ibm.com, tj@kernel.org, mingo@redhat.com,
	der.herr@hofr.at, dave@stgolabs.net, riel@redhat.com,
	viro@ZenIV.linux.org.uk, torvalds@linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Subject: [RFC PATCH 2/6] stop_machine: don't do for_each_cpu() twice in queue_stop_cpus_work()
Date: Fri, 26 Jun 2015 04:15:12 +0200	[thread overview]
Message-ID: <20150626021512.GA5697@redhat.com> (raw)
In-Reply-To: <20150626021455.GA5675@redhat.com>

queue_stop_cpus_work() can do everything in one for_each_cpu() loop.
This simplifies this code a bit, and this is also preparation for the
locking changes.

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:[~2015-06-26  2:17 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-26  2:14 [RFC PATCH 0/6] stop_machine: kill stop_cpus_mutex and stop_cpus_lock Oleg Nesterov
2015-06-26  2:15 ` [RFC PATCH 1/6] stop_machine: move cpu_stopper_task and stop_cpus_work into struct cpu_stopper Oleg Nesterov
2015-06-26  2:15 ` Oleg Nesterov [this message]
2015-06-26  2:15 ` [RFC PATCH 3/6] stop_machine: introduce stop_work_alloc() and stop_work_free() Oleg Nesterov
2015-06-26  2:15 ` [RFC PATCH 4/6] stop_machine: kill stop_cpus_mutex Oleg Nesterov
2015-06-26  2:15 ` [RFC PATCH 5/6] stop_machine: change stop_two_cpus() just use stop_cpu(), kill lg_double_lock/unlock Oleg Nesterov
2015-06-26  2:15 ` [RFC PATCH 6/6] stop_machine: optimize stop_work_alloc() Oleg Nesterov
2015-06-29  8:56   ` Peter Zijlstra
2015-06-26  2:31 ` [RFC PATCH 0/6] stop_machine: kill stop_cpus_mutex and stop_cpus_lock Oleg Nesterov
2015-06-26 12:23 ` Peter Zijlstra
2015-06-26 20:46   ` Oleg Nesterov
2015-06-29  4:02     ` Oleg Nesterov
2015-06-29  8:51       ` Peter Zijlstra
2015-06-30  1:08         ` Oleg Nesterov
2015-06-29  8:49     ` Peter Zijlstra
2015-06-30  1:03       ` Oleg Nesterov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20150626021512.GA5697@redhat.com \
    --to=oleg@redhat.com \
    --cc=dave@stgolabs.net \
    --cc=der.herr@hofr.at \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=paulmck@linux.vnet.ibm.com \
    --cc=peterz@infradead.org \
    --cc=riel@redhat.com \
    --cc=tj@kernel.org \
    --cc=torvalds@linux-foundation.org \
    --cc=viro@ZenIV.linux.org.uk \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.