Home
last modified time | relevance | path

Searched hist:"4468 a00f" (Results 1 – 1 of 1) sorted by relevance

/openbmc/linux/kernel/
H A Dworkqueue.c4468a00f Wed Feb 06 20:04:53 CST 2013 Lai Jiangshan <laijs@cn.fujitsu.com> workqueue: make work->data point to pool after try_to_grab_pending()

We plan to use work->data pointing to cwq as the synchronization
invariant when determining whether a given work item is on a locked
pool or not, which requires work->data pointing to cwq only while the
work item is queued on the associated pool.

With delayed_work updated not to overload work->data for target
workqueue recording, the only case where we still have off-queue
work->data pointing to cwq is try_to_grab_pending() which doesn't
update work->data after stealing a queued work item. There's no
reason for try_to_grab_pending() to not update work->data to point to
the pool instead of cwq, like the normal execution does.

This patch adds set_work_pool_and_keep_pending() which makes
work->data point to pool instead of cwq but keeps the pending bit
unlike set_work_pool_and_clear_pending() (surprise!).

After this patch, it's guaranteed that only queued work items point to
cwqs.

This patch doesn't introduce any visible behavior change.

tj: Renamed the new helper function to match
set_work_pool_and_clear_pending() and rewrote the description.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
4468a00f Wed Feb 06 20:04:53 CST 2013 Lai Jiangshan <laijs@cn.fujitsu.com> workqueue: make work->data point to pool after try_to_grab_pending()

We plan to use work->data pointing to cwq as the synchronization
invariant when determining whether a given work item is on a locked
pool or not, which requires work->data pointing to cwq only while the
work item is queued on the associated pool.

With delayed_work updated not to overload work->data for target
workqueue recording, the only case where we still have off-queue
work->data pointing to cwq is try_to_grab_pending() which doesn't
update work->data after stealing a queued work item. There's no
reason for try_to_grab_pending() to not update work->data to point to
the pool instead of cwq, like the normal execution does.

This patch adds set_work_pool_and_keep_pending() which makes
work->data point to pool instead of cwq but keeps the pending bit
unlike set_work_pool_and_clear_pending() (surprise!).

After this patch, it's guaranteed that only queued work items point to
cwqs.

This patch doesn't introduce any visible behavior change.

tj: Renamed the new helper function to match
set_work_pool_and_clear_pending() and rewrote the description.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>