2011-06-23 18:22:16

by Suresh Siddha

Subject: [patch v2 2/4] stop_machine: reorganize stop_cpus() implementation

From: Tejun Heo <[email protected]>

Refactor the queuing part of the stop cpus work from __stop_cpus() into
queue_stop_cpus_work().

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

Signed-off-by: Tejun Heo <[email protected]>
Signed-off-by: Suresh Siddha <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
---
kernel/stop_machine.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)

Index: linux-2.6-tip/kernel/stop_machine.c
===================================================================
--- linux-2.6-tip.orig/kernel/stop_machine.c
+++ linux-2.6-tip/kernel/stop_machine.c
@@ -136,10 +136,11 @@ DEFINE_MUTEX(stop_cpus_mutex);
/* static data for stop_cpus */
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 queue_stop_cpus_work(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 *cp
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 *cp
cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu),
&per_cpu(stop_cpus_work, cpu));
preempt_enable();
+}

+static int __stop_cpus(const struct cpumask *cpumask,
+ cpu_stop_fn_t fn, void *arg)
+{
+ struct cpu_stop_done done;
+
+ cpu_stop_init_done(&done, cpumask_weight(cpumask));
+ queue_stop_cpus_work(cpumask, fn, arg, &done);
wait_for_completion(&done.completion);
return done.executed ? done.ret : -ENOENT;
}

2011-06-27 23:16:57

by Tejun Heo

Subject: [tip:x86/mtrr] stop_machine: reorganize stop_cpus() implementation

Commit-ID: fd7355ba1e936487f5aae6fc058c6cb300e44a64
Gitweb: http://git.kernel.org/tip/fd7355ba1e936487f5aae6fc058c6cb300e44a64
Author: Tejun Heo <[email protected]>
AuthorDate: Thu, 23 Jun 2011 11:19:27 -0700
Committer: H. Peter Anvin <[email protected]>
CommitDate: Mon, 27 Jun 2011 15:17:07 -0700

stop_machine: reorganize stop_cpus() implementation

Refactor the queuing part of the stop cpus work from __stop_cpus() into
queue_stop_cpus_work().

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

Signed-off-by: Tejun Heo <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Suresh Siddha <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>
---
kernel/stop_machine.c | 16 ++++++++++++----
1 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 0cae1cc..4c89ee9 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -136,10 +136,11 @@ DEFINE_MUTEX(stop_cpus_mutex);
/* static data for stop_cpus */
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 queue_stop_cpus_work(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(const struct cpumask *cpumask,
+ cpu_stop_fn_t fn, void *arg)
+{
+ struct cpu_stop_done done;
+
+ cpu_stop_init_done(&done, cpumask_weight(cpumask));
+ queue_stop_cpus_work(cpumask, fn, arg, &done);
wait_for_completion(&done.completion);
return done.executed ? done.ret : -ENOENT;
}