Messages in this thread | | | Subject | Re: [PATCH 2/3] blk-core: introduce queue close feature | From | Bart Van Assche <> | Date | Wed, 05 Sep 2018 08:57:17 -0700 |
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On Wed, 2018-09-05 at 12:09 +0800, Jianchao Wang wrote: > blk queue freeze is often used to prevent new IO from entering > request queue. However, becuase we kill the percpu-ref > q_usage_counter when freeze queue, we have to drain the request > queue when unfreeze. This is unnecessary for just preventing new > IO. In addition, If there is IO timeout or other issue when unfreeze > the queue, the scenario could be very tricky. > > So we introduce BLK_QUEUE_GATE_CLOSED to implement a light-weight > queue close feature base on the queue_gate to prevent new IO from > comming in queue which will not need to drain the queue any more.
Does the "queue gate close" feature cause blk_get_request() / blk_mq_get_request() to block until blk_clear_queue_closed() is called? If so, I think we need a better name for this feature. How about calling these two operations suspend and resume?
Thanks,
Bart.
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