Messages in this thread |  | | From | Lai Jiangshan <> | Subject | [PATCH 00/13] workqueue: enhance locking and record global worker id for work data | Date | Fri, 1 Feb 2013 02:41:23 +0800 |
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Better Locking: ---------
We have a much complex way to find out on which pool a given work is queued on, mainly based on *mb() which is the most dangerous code and bad for readability. This series change the usage of CWQ bit and makes these code simpler. --PATCH 3,4,5
We have get_work_pool(), but it requires the caller do the later check and locking, we replace it which 3 better internal locking API. 1) More proper API and 2) merge the duplicated code and 3) simplify the caller. --PATCH 8,9,10
get_work_pool()/get_work_pool_id() are called everywhere, something they are overkill(called idr_find() unneeded) and indirectly(caller knows it is onq or not), we replace them with get_work_cwq()/offq_work_pool_id()/locking APIs. --PATCH 3,4,5,6,8,9,10
Safely/one-step searching and worker id: ----------------------------------------
We are planing to add non-std worker_pool, but old get_work_pool() or new lock_pool_executing_work() was not prepared for this plan, idr_find(pool_id) is unsafe when we introduce free-able non-std worker_pool. Although we can fix it by adding rcu to worker_pool. but "recording global worker id for work data and adding rcu to worker" is another way and more straight forward. We implement the later one, Now, lock_pool_executing_work() is ready for this plan. --PATCH 12,13
When every time we need to find out the running worker from a work, we need two searches: search work_pool from work's data, and search worker from hash. We record global worker id for work data and we only need one search. --PATCH 13
cleanup --PATCH 1,2,7,11
On top of tj/for-3.9 706026c2141113886f61e1ad2738c9a7723ec69c
Lai Jiangshan (13): workqueue: remove WORK_CPU_NONE workqueue: fix work_busy() workqueue: don't set work cwq until we queued it on pool workqueue: clear cwq when cancel the work workqueue: change queued detection and remove *mb()s workqueue: get pool id from work->data directly if it is offq workqueue: get pool from wq/cwq workqueue: add lock_pool_executing_work() workqueue: add lock_pool_queued_work() workqueue: add lock_pool_own_work() and remove get_work_pool() workqueue: allow more work_pool id space workqueue: add worker's global worker ID workqueue: record global worker ID instead of pool ID in work->data when off-queue
include/linux/workqueue.h | 24 ++-- kernel/workqueue.c | 428 +++++++++++++++++++++++-------------------- kernel/workqueue_internal.h | 1 + 3 files changed, 242 insertions(+), 211 deletions(-)
-- 1.7.7.6
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