linux-kernel - [PATCH 08/10] workqueue: assign overflowed flushers's flush color when queued

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]

Date:	Mon, 24 Sep 2012 18:07:10 +0800
From:	Lai Jiangshan <laijs@...fujitsu.com>
To:	Tejun Heo <tj@...nel.org>, linux-kernel@...r.kernel.org
Cc:	Lai Jiangshan <laijs@...fujitsu.com>
Subject: [PATCH 08/10] workqueue: assign overflowed flushers's flush color when queued

wq->work_color is unchanged between overflowed flusher queued on
 ->flusher_overflow and requeued on ->flusher_queue.

So we can assign overflowed flushers's flush color when they are queued
on ->flusher_overflow.

This patch makes the flusher's flush color more clear:
	flusher's flush color is the work color of the WQ
	when flush_workqueue() starts.

Remove an unneeded loop.

This patch doesn't make any functional difference.

Signed-off-by: Lai Jiangshan <laijs@...fujitsu.com>
---
 kernel/workqueue.c |   19 +++++++++----------
 1 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index be407e1..f687893 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2613,11 +2613,11 @@ void flush_workqueue(struct workqueue_struct *wq)
 	 */
 	flush_color = wq->work_color;
 	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 */
 		BUG_ON(!list_empty(&wq->flusher_overflow));
-		this_flusher.flush_color = flush_color;
 
 		if (!wq->first_flusher) {
 			/* no flush in progress, become the first flusher */
@@ -2643,8 +2643,8 @@ void flush_workqueue(struct workqueue_struct *wq)
 	} else {
 		/*
 		 * Oops, color space is full, wait on overflow queue.
-		 * The next flush completion will assign us
-		 * flush_color and transfer to flusher_queue.
+		 * The next flush completion will start flush for us
+		 * with freed flush color and transfer us to flusher_queue.
 		 */
 		list_add_tail(&this_flusher.list, &wq->flusher_overflow);
 	}
@@ -2684,15 +2684,14 @@ void flush_workqueue(struct workqueue_struct *wq)
 
 	/* one color has been freed, handle overflow queue */
 	if (!list_empty(&wq->flusher_overflow)) {
+		BUG_ON(list_first_entry(&wq->flusher_overflow,
+					struct wq_flusher,
+					list)->flush_color
+		       != wq->work_color);
 		/*
-		 * Assign the same color to all overflowed
-		 * flushers, advance work_color and append to
-		 * flusher_queue.  This is the start-to-wait
-		 * phase for these overflowed flushers.
+		 * start flush with the freed color and append
+		 * overflowed flushers to the flusher_queue.
 		 */
-		list_for_each_entry(tmp, &wq->flusher_overflow, list)
-			tmp->flush_color = wq->work_color;
-
 		list_splice_tail_init(&wq->flusher_overflow,
 				      &wq->flusher_queue);
 		workqueue_start_flush(wq);
-- 
1.7.4.4

--
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/