workqueue: reimplement work flushing using linked works

A work is linked to the next one by having WORK_STRUCT_LINKED bit set
and these links can be chained.  When a linked work is dispatched to a
worker, all linked works are dispatched to the worker's newly added
->scheduled queue and processed back-to-back.

Currently, as there's only single worker per cwq, having linked works
doesn't make any visible behavior difference.  This change is to
prepare for multiple shared workers per cpu.

Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Tejun Heo
2010-06-29 10:07:12 +02:00
parent c34056a3fd
commit affee4b294
2 changed files with 134 additions and 22 deletions

View File

@ -24,8 +24,9 @@ typedef void (*work_func_t)(struct work_struct *work);
enum {
WORK_STRUCT_PENDING_BIT = 0, /* work item is pending execution */
WORK_STRUCT_LINKED_BIT = 1, /* next work is linked to this one */
#ifdef CONFIG_DEBUG_OBJECTS_WORK
WORK_STRUCT_STATIC_BIT = 1, /* static initializer (debugobjects) */
WORK_STRUCT_STATIC_BIT = 2, /* static initializer (debugobjects) */
WORK_STRUCT_COLOR_SHIFT = 3, /* color for workqueue flushing */
#else
WORK_STRUCT_COLOR_SHIFT = 2, /* color for workqueue flushing */
@ -34,6 +35,7 @@ enum {
WORK_STRUCT_COLOR_BITS = 4,
WORK_STRUCT_PENDING = 1 << WORK_STRUCT_PENDING_BIT,
WORK_STRUCT_LINKED = 1 << WORK_STRUCT_LINKED_BIT,
#ifdef CONFIG_DEBUG_OBJECTS_WORK
WORK_STRUCT_STATIC = 1 << WORK_STRUCT_STATIC_BIT,
#else