On Tue, Dec 05, 2017 at 04:41:46PM +0000, Bart Van Assche wrote: > On Wed, 2017-12-06 at 00:28 +0800, Ming Lei wrote: > > This is still a workaround for RESTART, see my comment before: > > > > https://marc.info/?l=linux-block&m=151217500929341&w=2 > > A quote from that e-mail: "The theory about using BLK_MQ_S_SCHED_RESTART in > current way is that we mark it after requests are added to hctx->dispatch". > Reading that makes me wonder whether you understand the purpose of the > BLK_MQ_S_SCHED_RESTART flag? That flag is not set after requests are added > to the dispatch list but after requests have been *removed*. The purpose of > that flag is to detect whether another thread has run the queue after > requests were removed from the dispatch list and before these were readded. > If so, the queue needs to be rerun. If you want to discuss that, please reply on that thread of '[PATCH 4/7] blk-mq: Avoid that request processing sta', I will reply on you there too. -- Ming
