On Tue, Aug 30, 2016 at 11:29:51PM +0530, Bhaktipriya Shridhar wrote: > The workqueue "irqfd_cleanup_wq" queues a single work item > &irqfd->shutdown and hence doesn't require ordering. It is a host-wide > workqueue for issuing deferred shutdown requests aggregated from all > vm* instances. It is not being used on a memory reclaim path. > Hence, it has been converted to use system_wq. > The work item has been flushed in kvm_irqfd_release(). > > The workqueue "wqueue" queues a single work item &timer->expired > and hence doesn't require ordering. Also, it is not being used on > a memory reclaim path. Hence, it has been converted to use system_wq. > > System workqueues have been able to handle high level of concurrency > for a long time now and hence it's not required to have a singlethreaded > workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue > created with create_singlethread_workqueue(), system_wq allows multiple > work items to overlap executions even on the same CPU; however, a > per-cpu workqueue doesn't have any CPU locality or global ordering > guarantee unless the target CPU is explicitly specified and thus the > increase of local concurrency shouldn't make any difference. > > Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@xxxxxxxxx> Acked-by: Tejun Heo <tj@xxxxxxxxxx> Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
