The patch titled
Handle CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASE in workqueue_cpu_callback
has been added to the -mm tree. Its filename is
handle-cpu_lock_acquire-and-cpu_lock_release-in-workqueue_cpu_callback.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Handle CPU_LOCK_ACQUIRE and CPU_LOCK_RELEASE in workqueue_cpu_callback
From: Gautham R Shenoy <ego@xxxxxxxxxx>
In hot-cpu callback function workqueue_cpu_callback, lock the workqueue_mutex
under CPU_LOCK_ACQUIRE and release it under CPU_LOCK_RELEASE.
This eliminates handling of redundant events namely CPU_DOWN_PREPARE and
CPU_DOWN_FAILED.
Signed-off-by: Gautham R Shenoy <ego@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
kernel/workqueue.c | 18 +++++++-----------
1 files changed, 7 insertions(+), 11 deletions(-)
diff -puN kernel/workqueue.c~handle-cpu_lock_acquire-and-cpu_lock_release-in-workqueue_cpu_callback kernel/workqueue.c
--- a/kernel/workqueue.c~handle-cpu_lock_acquire-and-cpu_lock_release-in-workqueue_cpu_callback
+++ a/kernel/workqueue.c
@@ -651,8 +651,11 @@ static int __devinit workqueue_cpu_callb
struct workqueue_struct *wq;
switch (action) {
- case CPU_UP_PREPARE:
+ case CPU_LOCK_ACQUIRE:
mutex_lock(&workqueue_mutex);
+ break;
+
+ case CPU_UP_PREPARE:
/* Create a new workqueue thread for it. */
list_for_each_entry(wq, &workqueues, list) {
if (!create_workqueue_thread(wq, hotcpu)) {
@@ -671,7 +674,6 @@ static int __devinit workqueue_cpu_callb
kthread_bind(cwq->thread, hotcpu);
wake_up_process(cwq->thread);
}
- mutex_unlock(&workqueue_mutex);
break;
case CPU_UP_CANCELED:
@@ -683,15 +685,6 @@ static int __devinit workqueue_cpu_callb
any_online_cpu(cpu_online_map));
cleanup_workqueue_thread(wq, hotcpu);
}
- mutex_unlock(&workqueue_mutex);
- break;
-
- case CPU_DOWN_PREPARE:
- mutex_lock(&workqueue_mutex);
- break;
-
- case CPU_DOWN_FAILED:
- mutex_unlock(&workqueue_mutex);
break;
case CPU_DEAD:
@@ -699,6 +692,9 @@ static int __devinit workqueue_cpu_callb
cleanup_workqueue_thread(wq, hotcpu);
list_for_each_entry(wq, &workqueues, list)
take_over_work(wq, hotcpu);
+ break;
+
+ case CPU_LOCK_RELEASE:
mutex_unlock(&workqueue_mutex);
break;
}
_
Patches currently in -mm which might be from ego@xxxxxxxxxx are
git-cpufreq.patch
extend-notifier_call_chain-to-count-nr_calls-made.patch
define-and-use-new-eventscpu_lock_acquire-and-cpu_lock_release.patch
define-and-use-new-eventscpu_lock_acquire-and-cpu_lock_release-fix.patch
eliminate-lock_cpu_hotplug-in-kernel-schedc.patch
handle-cpu_lock_acquire-and-cpu_lock_release-in-workqueue_cpu_callback.patch
-
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