summaryrefslogtreecommitdiffstats
path: root/include/linux/workqueue.h
diff options
context:
space:
mode:
authorTejun Heo <tj@kernel.org>2012-08-03 10:30:46 -0700
committerTejun Heo <tj@kernel.org>2012-08-03 10:30:46 -0700
commitb5490077274482efde57a50b060b99bc839acd45 (patch)
treedae1b67fa7b1c18d116fe97765bad1e52786e7aa /include/linux/workqueue.h
parentbf4ede014ea886b71ef71368738da35b316cb7c0 (diff)
downloadop-kernel-dev-b5490077274482efde57a50b060b99bc839acd45.zip
op-kernel-dev-b5490077274482efde57a50b060b99bc839acd45.tar.gz
workqueue: introduce WORK_OFFQ_FLAG_*
Low WORK_STRUCT_FLAG_BITS bits of work_struct->data contain WORK_STRUCT_FLAG_* and flush color. If the work item is queued, the rest point to the cpu_workqueue with WORK_STRUCT_CWQ set; otherwise, WORK_STRUCT_CWQ is clear and the bits contain the last CPU number - either a real CPU number or one of WORK_CPU_*. Scheduled addition of mod_delayed_work[_on]() requires an additional flag, which is used only while a work item is off queue. There are more than enough bits to represent off-queue CPU number on both 32 and 64bits. This patch introduces WORK_OFFQ_FLAG_* which occupy the lower part of the @work->data high bits while off queue. This patch doesn't define any actual OFFQ flag yet. Off-queue CPU number is now shifted by WORK_OFFQ_CPU_SHIFT, which adds the number of bits used by OFFQ flags to WORK_STRUCT_FLAG_SHIFT, to make room for OFFQ flags. To avoid shift width warning with large WORK_OFFQ_FLAG_BITS, ulong cast is added to WORK_STRUCT_NO_CPU and, just in case, BUILD_BUG_ON() to check that there are enough bits to accomodate off-queue CPU number is added. This patch doesn't make any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'include/linux/workqueue.h')
-rw-r--r--include/linux/workqueue.h8
1 files changed, 7 insertions, 1 deletions
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index ab95fef..f562674 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -68,9 +68,15 @@ enum {
WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT +
WORK_STRUCT_COLOR_BITS,
+ /* data contains off-queue information when !WORK_STRUCT_CWQ */
+ WORK_OFFQ_FLAG_BASE = WORK_STRUCT_FLAG_BITS,
+ WORK_OFFQ_FLAG_BITS = 0,
+ WORK_OFFQ_CPU_SHIFT = WORK_OFFQ_FLAG_BASE + WORK_OFFQ_FLAG_BITS,
+
+ /* convenience constants */
WORK_STRUCT_FLAG_MASK = (1UL << WORK_STRUCT_FLAG_BITS) - 1,
WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK,
- WORK_STRUCT_NO_CPU = WORK_CPU_NONE << WORK_STRUCT_FLAG_BITS,
+ WORK_STRUCT_NO_CPU = (unsigned long)WORK_CPU_NONE << WORK_OFFQ_CPU_SHIFT,
/* bit mask for work_busy() return values */
WORK_BUSY_PENDING = 1 << 0,
OpenPOWER on IntegriCloud