From: Lai Jiangshan <laijs@cn.fujitsu.com>
To: Tejun Heo <tj@kernel.org>, linux-kernel@vger.kernel.org
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Subject: [PATCH 10/10] workqueue: remove wq->flush_color
Date: Mon, 24 Sep 2012 18:07:12 +0800 [thread overview]
Message-ID: <1348481238-6138-11-git-send-email-laijs@cn.fujitsu.com> (raw)
In-Reply-To: <1348481238-6138-1-git-send-email-laijs@cn.fujitsu.com>
Use wq->first_flusher->flush_color instead.
If current task is the first_flusher, we use @flush_color
or work_next_color(flush_color) directly.
This patch doesn't make any functional difference.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
kernel/workqueue.c | 52 ++++++++++++++++++++--------------------------------
1 files changed, 20 insertions(+), 32 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index d78fe08..e703659 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -248,7 +248,6 @@ struct workqueue_struct {
struct mutex flush_mutex; /* protects wq flushing */
int work_color; /* F: current work color */
- int flush_color; /* F: current flush color */
atomic_t nr_cwqs_to_flush[WORK_NR_COLORS];
struct wq_flusher *first_flusher; /* F: first flusher */
struct list_head flusher_queue; /* F: flush waiters */
@@ -2555,7 +2554,7 @@ static bool workqueue_start_flush(struct workqueue_struct *wq)
bool wait = false;
unsigned int cpu;
- BUG_ON(next_color == wq->flush_color);
+ BUG_ON(next_color == wq->first_flusher->flush_color);
wq->work_color = next_color;
BUG_ON(atomic_read(&wq->nr_cwqs_to_flush[flush_color]));
@@ -2614,29 +2613,23 @@ void flush_workqueue(struct workqueue_struct *wq)
next_color = work_next_color(wq->work_color);
this_flusher.flush_color = flush_color;
- if (next_color != wq->flush_color) {
- /* Color space is not full */
- if (!wq->first_flusher) {
- /* no flush in progress, become the first flusher */
- BUG_ON(wq->flush_color != flush_color);
-
- wq->first_flusher = &this_flusher;
-
- if (!workqueue_start_flush(wq)) {
- /* nothing to flush, done */
- wq_dec_flusher_ref(wq, flush_color);
- wq->flush_color = next_color;
- wq->first_flusher = NULL;
- goto out_unlock;
- }
+ if (!wq->first_flusher) {
+ /* no flush in progress, become the first flusher */
+ wq->first_flusher = &this_flusher;
+ if (!workqueue_start_flush(wq)) {
+ /* nothing to flush, done */
wq_dec_flusher_ref(wq, flush_color);
- } else {
- /* wait in queue */
- BUG_ON(wq->flush_color == this_flusher.flush_color);
- list_add_tail(&this_flusher.list, &wq->flusher_queue);
- workqueue_start_flush(wq);
+ wq->first_flusher = NULL;
+ goto out_unlock;
}
+
+ wq_dec_flusher_ref(wq, flush_color);
+ } else if (next_color != wq->first_flusher->flush_color) {
+ /* Color space is not full, wait in queue */
+ BUG_ON(wq->first_flusher->flush_color == flush_color);
+ list_add_tail(&this_flusher.list, &wq->flusher_queue);
+ workqueue_start_flush(wq);
} else {
/*
* Oops, color space is full, queue it without starting flush.
@@ -2663,21 +2656,17 @@ void flush_workqueue(struct workqueue_struct *wq)
BUG_ON(wq->first_flusher != &this_flusher);
BUG_ON(!list_empty(&this_flusher.list));
- BUG_ON(wq->flush_color != this_flusher.flush_color);
/* complete all the flushers sharing the current flush color */
list_for_each_entry_safe(next, tmp, &wq->flusher_queue, list) {
- if (next->flush_color != wq->flush_color)
+ if (next->flush_color != flush_color)
break;
list_del_init(&next->list);
complete(&next->done);
}
- /* this flush_color is finished, advance by one */
- wq->flush_color = work_next_color(wq->flush_color);
-
if (list_empty(&wq->flusher_queue)) {
- BUG_ON(wq->flush_color != wq->work_color);
+ BUG_ON(work_next_color(flush_color) != wq->work_color);
wq->first_flusher = NULL;
goto out_unlock;
}
@@ -2686,9 +2675,6 @@ void flush_workqueue(struct workqueue_struct *wq)
* Need to flush more colors. Make the next flusher
* the new first flusher and arm it.
*/
- BUG_ON(wq->flush_color == wq->work_color);
- BUG_ON(wq->flush_color != next->flush_color);
-
last = list_entry(wq->flusher_queue.prev, struct wq_flusher, list);
list_del_init(&next->list);
wq->first_flusher = next;
@@ -2698,9 +2684,11 @@ void flush_workqueue(struct workqueue_struct *wq)
workqueue_start_flush(wq);
BUG_ON(work_next_color(last->flush_color) != wq->work_color);
+ BUG_ON(work_next_color(flush_color) != next->flush_color);
+ BUG_ON(next->flush_color == wq->work_color);
/* arm new first flusher */
- wq_dec_flusher_ref(wq, wq->flush_color);
+ wq_dec_flusher_ref(wq, next->flush_color);
out_unlock:
mutex_unlock(&wq->flush_mutex);
--
1.7.4.4
next prev parent reply other threads:[~2012-09-24 10:05 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-24 10:07 [PATCH 00/10] workqueue: restructure flush_workqueue() and start all flusher at the same time Lai Jiangshan
2012-09-24 10:07 ` [PATCH 01/10] workqueue: always pass flush responsibility to next Lai Jiangshan
2012-09-24 10:07 ` [PATCH 02/10] workqueue: remove unneeded check Lai Jiangshan
2012-09-24 10:07 ` [PATCH 03/10] workqueue: remove while(true) Lai Jiangshan
2012-09-24 10:07 ` [PATCH 04/10] workqueue: use nr_cwqs_to_flush array Lai Jiangshan
2012-09-24 10:07 ` [PATCH 05/10] workqueue: add wq_dec_flusher_ref() Lai Jiangshan
2012-09-24 10:07 ` [PATCH 06/10] workqueue: start all flusher at the same time Lai Jiangshan
2012-09-24 10:07 ` [PATCH 07/10] workqueue: simplify flush_workqueue_prep_cwqs() Lai Jiangshan
2012-09-24 10:07 ` [PATCH 08/10] workqueue: assign overflowed flushers's flush color when queued Lai Jiangshan
2012-09-24 10:07 ` [PATCH 09/10] workqueue: remove flusher_overflow Lai Jiangshan
2012-09-24 10:07 ` Lai Jiangshan [this message]
2012-09-24 20:39 ` [PATCH 00/10] workqueue: restructure flush_workqueue() and start all flusher at the same time Tejun Heo
2012-09-25 9:02 ` Lai Jiangshan
2012-09-25 20:14 ` Tejun Heo
2012-09-25 9:02 ` Lai Jiangshan
2012-09-25 20:24 ` Tejun Heo
2012-09-26 4:48 ` Lai Jiangshan
2012-09-26 16:49 ` Tejun Heo
2012-09-26 17:04 ` Tejun Heo
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