On Tue, Jul 11, 2017 at 12:39:35PM -0600, Jens Axboe wrote: > On 07/11/2017 12:21 PM, Ming Lei wrote: > > diff --git a/block/blk-mq.h b/block/blk-mq.h > > index 60b01c0309bc..c4516d2a2d2c 100644 > > --- a/block/blk-mq.h > > +++ b/block/blk-mq.h > > @@ -133,4 +133,13 @@ static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx) > > return hctx->nr_ctx && hctx->tags; > > } > > > > +/* borrowed from bcache */ > > +#define ewma_add(ewma, val, weight, factor) \ > > +({ \ > > + (ewma) *= (weight) - 1; \ > > + (ewma) += (val) << factor; \ > > + (ewma) /= (weight); \ > > + (ewma) >> factor; \ > > +}) > > Just put that in blk_mq_update_req_dispatch_busy(), or at least make it > a static function in blk-mq.c above that function. You don't use factor > at all. OK, will do it in V2. -- Ming