On Tue, Jul 30, 2013 at 09:57:51AM -0400, Tejun Heo wrote: > Hello, > > On Tue, Jul 30, 2013 at 09:07:08PM +0800, Shaohua Li wrote: > > Ok, I should explain here. I can't add a work_struct for each stripe, because > > this will stress workqueue very hard. My system handles > 1M/s stripes, which > > makes workqueue pool lock contended very hard. > > It doesn't have to be embedding work_struct in each stripe and > schduling them altogether. It's more about scheduling "work units" > rather than "workers" - ie. letting each scheduled work item handle > single work unit rather than making it dispatch multiple work items. > It may make controlling concurrency a bit more interesting but you can > always do it with workqueue_set_max_active(), which is the intended > usage anyway. stripe is the work unit actually. As I said, if I queue a work for each stripe, just queue_work() will make the system blast because of the pwq->pool->lock contention. dispatching one work has another side effect that I can't add block plug. Since this is the queue stage concurrency problem, workqueue_set_max_active() doesn't help. Thanks, Shaohua -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
