Messages in this thread | | | Date | Tue, 13 May 2014 14:55:24 +0800 | From | Lai Jiangshan <> | Subject | Re: [PATCH 10/10 V2] workqueue: use generic attach/detach routine for rescuers |
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On 05/13/2014 06:05 AM, Tejun Heo wrote: > On Mon, May 12, 2014 at 02:56:22PM +0800, Lai Jiangshan wrote: >> There are several problems with the code that rescuers bind itself to the pool' >> cpumask >> 1) It uses a way different from the normal workers to bind to the cpumask >> So we can't maintain the normal/rescuer workers under the same framework. >> 2) The the code of cpu-binding for rescuer is complicated >> 3) If one or more cpuhotplugs happen while the rescuer processes the >> scheduled works, the rescuer may not be correctly bound to the cpumask of >> the pool. This is allowed behavior, but is not good. It will be better >> if the cpumask of the rescuer is always kept coordination with the pool >> across any cpuhotplugs. >> >> Using generic attach/detach routine will solve the above problems, >> and result much more simple code. >> >> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> >> static struct worker *alloc_worker(void) >> { >> struct worker *worker; >> @@ -2343,8 +2279,9 @@ repeat: >> >> spin_unlock_irq(&wq_mayday_lock); >> >> - /* migrate to the target cpu if possible */ >> - worker_maybe_bind_and_lock(pool); >> + worker_attach_to_pool(rescuer, pool); >> + >> + spin_lock_irq(&pool->lock); >> rescuer->pool = pool; >> >> /* >> @@ -2357,6 +2294,11 @@ repeat: >> move_linked_works(work, scheduled, &n); >> >> process_scheduled_works(rescuer); >> + spin_unlock_irq(&pool->lock); >> + >> + worker_detach_from_pool(rescuer, pool); >> + >> + spin_lock_irq(&pool->lock); > > Ah, right, this is how it's used. Yeah, it makes sense. In a long > patchset, it usually helps to mention your intentions when structuring > functions tho. When you're separating out detach_from_pool, just > mention that the function will later be used to make rescuers use the
In patch3, the intention for separating out detach_from_pool() is only for aync-destruction and it is used for worker_thread().
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