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. -- Jens Axboe