user/sven/linux.git/kernel/workqueue.c, branch v3.17

Merge branch 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

2014-08-04T17:09:27Z

Pull percpu updates from Tejun Heo: - Major reorganization of percpu header files which I think makes things a lot more readable and logical than before. - percpu-refcount is updated so that it requires explicit destruction and can be reinitialized if necessary. This was pulled into the block tree to replace the custom percpu refcnting implemented in blk-mq. - In the process, percpu and percpu-refcount got cleaned up a bit * 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (21 commits) percpu-refcount: implement percpu_ref_reinit() and percpu_ref_is_zero() percpu-refcount: require percpu_ref to be exited explicitly percpu-refcount: use unsigned long for pcpu_count pointer percpu-refcount: add helpers for ->percpu_count accesses percpu-refcount: one bit is enough for REF_STATUS percpu-refcount, aio: use percpu_ref_cancel_init() in ioctx_alloc() workqueue: stronger test in process_one_work() workqueue: clear POOL_DISASSOCIATED in rebind_workers() percpu: Use ALIGN macro instead of hand coding alignment calculation percpu: invoke __verify_pcpu_ptr() from the generic part of accessors and operations percpu: preffity percpu header files percpu: use raw_cpu_*() to define __this_cpu_*() percpu: reorder macros in percpu header files percpu: move {raw|this}_cpu_*() definitions to include/linux/percpu-defs.h percpu: move generic {raw|this}_cpu_*_N() definitions to include/asm-generic/percpu.h percpu: only allow sized arch overrides for {raw|this}_cpu_*() ops percpu: reorganize include/linux/percpu-defs.h percpu: move accessors from include/linux/percpu.h to percpu-defs.h percpu: include/asm-generic/percpu.h should contain only arch-overridable parts percpu: introduce arch_raw_cpu_ptr() ...

Merge branch 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

2014-08-04T17:04:44Z

Pull workqueue updates from Tejun Heo: "Lai has been doing a lot of cleanups of workqueue and kthread_work. No significant behavior change. Just a lot of cleanups all over the place. Some are a bit invasive but overall nothing too dangerous" * 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: kthread_work: remove the unused wait_queue_head kthread_work: wake up worker only when the worker is idle workqueue: use nr_node_ids instead of wq_numa_tbl_len workqueue: remove the misnamed out_unlock label in get_unbound_pool() workqueue: remove the stale comment in pwq_unbound_release_workfn() workqueue: move rescuer pool detachment to the end workqueue: unfold start_worker() into create_worker() workqueue: remove @wakeup from worker_set_flags() workqueue: remove an unneeded UNBOUND test before waking up the next worker workqueue: wake regular worker if need_more_worker() when rescuer leave the pool workqueue: alloc struct worker on its local node workqueue: reuse the already calculated pwq in try_to_grab_pending() workqueue: stronger test in process_one_work() workqueue: clear POOL_DISASSOCIATED in rebind_workers() workqueue: sanity check pool->cpu in wq_worker_sleeping() workqueue: clear leftover flags when detached workqueue: remove useless WARN_ON_ONCE() workqueue: use schedule_timeout_interruptible() instead of open code workqueue: remove the empty check in too_many_workers() workqueue: use "pool->cpu < 0" to stand for an unbound pool

workqueue: use nr_node_ids instead of wq_numa_tbl_len

2014-07-22T16:10:39Z

They are the same and nr_node_ids is provided by the memory subsystem. Signed-off-by: Lai Jiangshan Signed-off-by: Tejun Heo

workqueue: remove the misnamed out_unlock label in get_unbound_pool()

2014-07-22T16:10:39Z

After the locking was moved up to the caller of the get_unbound_pool(), out_unlock label doesn't need to do any unlock operation and the name became bad, so we just remove this label, and the only usage-site "goto out_unlock" is subsituted to "return pool". Signed-off-by: Lai Jiangshan Signed-off-by: Tejun Heo

workqueue: remove the stale comment in pwq_unbound_release_workfn()

2014-07-22T16:10:39Z

In 75ccf5950f82 ("workqueue: prepare flush_workqueue() for dynamic creation and destrucion of unbound pool_workqueues"), a comment about the synchronization for the pwq in pwq_unbound_release_workfn() was added. The comment claimed the flush_mutex wasn't strictly necessary, it was correct in that time, due to the pwq was protected by workqueue_lock. But it is incorrect now since the wq->flush_mutex was renamed to wq->mutex and workqueue_lock was removed, the wq->mutex is strictly needed. But the comment was miss-updated when the synchronization was changed. This patch removes the incorrect comments and doesn't add any new comment to explain why wq->mutex is needed here, which is definitely obvious and wq->pwqs_node has "WQ" notation in its definition which is better comment. The old commit mentioned above also introduced a comment in link_pwq() about the synchronization. This comment is also removed in this patch since the whole link_pwq() is proteced by wq->mutex. Signed-off-by: Lai Jiangshan Signed-off-by: Tejun Heo

workqueue: move rescuer pool detachment to the end

2014-07-22T16:10:39Z

In 51697d393922 ("workqueue: use generic attach/detach routine for rescuers"), The rescuer detaches itself from the pool before put_pwq() so that the put_unbound_pool() will not destroy the rescuer-attached pool. It is unnecessary. worker_detach_from_pool() can be used as the last statement to access to the pool just like the regular workers, put_unbound_pool() will wait for it to detach and then free the pool. So we move the worker_detach_from_pool() down, make it coincide with the regular workers. tj: Minor description update. Signed-off-by: Lai Jiangshan Signed-off-by: Tejun Heo

workqueue: unfold start_worker() into create_worker()

2014-07-22T16:10:39Z

Simply unfold the code of start_worker() into create_worker() and remove the original start_worker() and create_and_start_worker(). The only trade-off is the introduced overhead that the pool->lock is released and regrabbed after the newly worker is started. The overhead is acceptible since the manager is slow path. And because this new locking behavior, the newly created worker may grab the lock earlier than the manager and go to process work items. In this case, the recheck need_to_create_worker() may be true as expected and the manager goes to restart which is the correct behavior. tj: Minor updates to description and comments. Signed-off-by: Lai Jiangshan Signed-off-by: Tejun Heo

workqueue: remove @wakeup from worker_set_flags()

2014-07-22T16:08:36Z

worker_set_flags() has only two callers, each specifying %true and %false for @wakeup. Let's push the wake up to the caller and remove @wakeup from worker_set_flags(). The caller can use the following instead if wakeup is necessary: worker_set_flags(); if (need_more_worker(pool)) wake_up_worker(pool); This makes the code simpler. This patch doesn't introduce behavior changes. tj: Updated description and comments. Signed-off-by: Lai Jiangshan Signed-off-by: Tejun Heo

workqueue: remove an unneeded UNBOUND test before waking up the next worker

2014-07-22T14:37:52Z

In process_one_work(): if ((worker->flags & WORKER_UNBOUND) && need_more_worker(pool)) wake_up_worker(pool); the first test is unneeded. Even if the first test is removed, it doesn't affect the wake-up logic for WORKER_UNBOUND, and it will not introduce any useless wake-ups for normal per-cpu workers since nr_running is always >= 1. It will introduce useless/redundant wake-ups for CPU_INTENSIVE, but this case is rare and the next patch will also remove this redundant wake-up. tj: Minor updates to the description and comment. Signed-off-by: Lai Jiangshan Signed-off-by: Tejun Heo

workqueue: wake regular worker if need_more_worker() when rescuer leave the pool

2014-07-18T22:46:11Z

We don't need to wake up regular worker when nr_running==1, so need_more_worker() is sufficient here. And need_more_worker() gives us better readability due to the name of "keep_working()" implies the rescuer should keep working now but the rescuer is actually leaving. Signed-off-by: Lai Jiangshan Signed-off-by: Tejun Heo