linux-kernel - [PATCH 2/3] stop_machine: reorganize stop

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1308071218-5912-3-git-send-email-tj@kernel.org>
Date:	Tue, 14 Jun 2011 19:06:57 +0200
From:	Tejun Heo <tj@...nel.org>
To:	x86@...nel.org, mingo@...e.hu, akpm@...ux-foundation.org,
	torvalds@...ux-foundation.org, suresh.b.siddha@...el.com,
	a.p.zijlstra@...llo.nl, linux-kernel@...r.kernel.org
Cc:	Tejun Heo <tj@...nel.org>
Subject: [PATCH 2/3] stop_machine: reorganize stop_cpus() implementation

Split __stop_cpus() into stop_cpus_queue() and stop_cpus_locked().
The former handles only the queueing part.  The latter uses the queue
function and is functionally equivalent to __stop_cpus().

The reorganization is to help future improvements to stop_machine()
and doesn't introduce any behavior difference.

Signed-off-by: Tejun Heo <tj@...nel.org>
Cc: Ingo Molnar <mingo@...e.hu>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Suresh Siddha <suresh.b.siddha@...el.com>
Cc: Peter Zijlstra <a.p.zijlstra@...llo.nl>
---
 kernel/stop_machine.c |   20 ++++++++++++++------
 1 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 3d3f47d..198973f 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -136,10 +136,11 @@ void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg,
 static DEFINE_MUTEX(stop_cpus_mutex);
 static DEFINE_PER_CPU(struct cpu_stop_work, stop_cpus_work);
 
-int __stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg)
+static void stop_cpus_queue(const struct cpumask *cpumask,
+			    cpu_stop_fn_t fn, void *arg,
+			    struct cpu_stop_done *done)
 {
 	struct cpu_stop_work *work;
-	struct cpu_stop_done done;
 	unsigned int cpu;
 
 	/* initialize works and done */
@@ -147,9 +148,8 @@ int __stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg)
 		work = &per_cpu(stop_cpus_work, cpu);
 		work->fn = fn;
 		work->arg = arg;
-		work->done = &done;
+		work->done = done;
 	}
-	cpu_stop_init_done(&done, cpumask_weight(cpumask));
 
 	/*
 	 * Disable preemption while queueing to avoid getting
@@ -161,7 +161,15 @@ int __stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg)
 		cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu),
 				    &per_cpu(stop_cpus_work, cpu));
 	preempt_enable();
+}
 
+static int stop_cpus_locked(const struct cpumask *cpumask,
+			    cpu_stop_fn_t fn, void *arg)
+{
+	struct cpu_stop_done done;
+
+	cpu_stop_init_done(&done, cpumask_weight(cpumask));
+	stop_cpus_queue(cpumask, fn, arg, &done);
 	wait_for_completion(&done.completion);
 	return done.executed ? done.ret : -ENOENT;
 }
@@ -200,7 +208,7 @@ int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg)
 
 	/* static works are used, process one request at a time */
 	mutex_lock(&stop_cpus_mutex);
-	ret = __stop_cpus(cpumask, fn, arg);
+	ret = stop_cpus_locked(cpumask, fn, arg);
 	mutex_unlock(&stop_cpus_mutex);
 	return ret;
 }
@@ -230,7 +238,7 @@ int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg)
 	/* static works are used, process one request at a time */
 	if (!mutex_trylock(&stop_cpus_mutex))
 		return -EAGAIN;
-	ret = __stop_cpus(cpumask, fn, arg);
+	ret = stop_cpus_locked(cpumask, fn, arg);
 	mutex_unlock(&stop_cpus_mutex);
 	return ret;
 }
-- 
1.7.5.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/