lkml.org 
[lkml]   [2013]   [Feb]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH 1/4] workqueue: allow more off-queue flag space
From 4acd43237af61d55ac128bbaf46ca092d560809c Mon Sep 17 00:00:00 2001
From: Lai Jiangshan <laijs@cn.fujitsu.com>
Date: Tue, 19 Feb 2013 12:17:01 -0800

When a work item is off-queue, its work->data contains WORK_STRUCT_*
and WORK_OFFQ_* flags. As WORK_OFFQ_* flags are used only while a
work item is off-queue, it can occupy bits of work->data which aren't
used while off-queue. WORK_OFFQ_* currently only use bits used by
on-queue CWQ pointer. As color bits aren't used while off-queue,
there's no reason to not use them.

Lower WORK_OFFQ_FLAG_BASE from WORK_STRUCT_FLAG_BITS to
WORK_STRUCT_COLOR_SHIFT thus giving 4 more bits to off-queue flag
space which is also used to record worker_pool ID while off-queue.

This doesn't introduce any visible behavior difference.

tj: Rewrote the description.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
Applied to wq/for-3.10-tmp. Note that I'm gonna reabse the branch
once 3.9-rc1 is out.

Thanks.

include/linux/workqueue.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 8afab27..5bd030f 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -68,7 +68,7 @@ enum {
WORK_STRUCT_COLOR_BITS,

/* data contains off-queue information when !WORK_STRUCT_PWQ */
- WORK_OFFQ_FLAG_BASE = WORK_STRUCT_FLAG_BITS,
+ WORK_OFFQ_FLAG_BASE = WORK_STRUCT_COLOR_SHIFT,

WORK_OFFQ_CANCELING = (1 << WORK_OFFQ_FLAG_BASE),

--
1.8.1


\
 
 \ /
  Last update: 2013-02-19 22:03    [W:3.134 / U:0.064 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site