On Wed, Sep 13, 2023 at 03:16:12PM +0000, chengming.zhou@xxxxxxxxx wrote: > From: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx> > > There is a limit that batched queue_rqs() can't work on shared tags > queue, since the account of active requests can't be done there. > > Now we account the active requests only in blk_mq_get_driver_tag(), > which is not the time we get driver tag actually (with none elevator). > > To support batched queue_rqs() on shared tags queue, we move the > account of active requests to where we get the driver tag: > > 1. none elevator: blk_mq_get_tags() and blk_mq_get_tag() > 2. other elevator: __blk_mq_alloc_driver_tag() > > This is clearer and match with the unaccount side, which just happen > when we put the driver tag. > > The other good point is that we don't need RQF_MQ_INFLIGHT trick > anymore, which used to avoid double account of flush request. > Now we only account when actually get the driver tag, so all is good. > We will remove RQF_MQ_INFLIGHT in the next patch. RQF_MQ_INFLIGHT is only set for BLK_MQ_F_TAG_QUEUE_SHARED, so we can avoid the extra atomic accounting for !BLK_MQ_F_TAG_QUEUE_SHARED. But now your patch switches to account unconditionally by removing RQF_MQ_INFLIGHT, not friendly for !BLK_MQ_F_TAG_QUEUE_SHARED. Thanks, Ming
