Messages in this thread | | | Date | Thu, 1 May 2014 16:51:47 +0200 | From | Frederic Weisbecker <> | Subject | Re: [PATCH 4/4] workqueue: Handle ordered workqueues on cpumask_unbounds change |
| |
On Thu, Apr 24, 2014 at 11:33:20AM -0400, Tejun Heo wrote: > On Thu, Apr 24, 2014 at 04:37:36PM +0200, Frederic Weisbecker wrote: > > Ordered unbound workqueues need some special care if we want to > > modify their CPU affinity. These can't be simply handled through > > apply_workqueue_attrs() since it works by hot plugging worker pools > > which has parallelism side effects and this would break ordering. > > > > The way we solve this is to change the affinity of the (presumaly > > unique) worker backing the ordered workqueues. > > > > NOTE: Now like Lai said, there may be bad side effects on this because > > ordered wq may share their worker pool with non-ordered workqueues. > > So changing the affinity of the worker itself is not a nice solution. > > This patch is very likely to be replaced by Lai's patch > > "workqueue: allow changing attributions of ordered workqueue" > > https://lkml.org/lkml/2014/4/15/181 > > Yeah, it bothers me that we're taking two completely different > approaches for ordered and !ordered workqueues. The only difference > between them is concurrency and it probably would be a better idea to > address that directly.
Yeah I've tried with Lai's patch and it seems to work like a charm so next version will likely be better.
| |