On Wed, Nov 10, 2021 at 10:14:07AM +0100, Christoph Hellwig wrote: > Hi Jens and Ming, > > I've been looking into properly supporting queue freezing for bio based > drivers (that is only release q_usage_counter on bio completion for them). > And the deeper I look into the code the more I'm confused by us having > the blk_mq_quiesce* interface in addition to blk_freeze_queue. What > is a good reason to do a quiesce separately from a freeze? freeze can make sure that all requests are done, quiesce can make sure that dispatch critical area(covered by hctx lock/unlock) is done. Thanks, Ming
