On Fri, 2018-04-27 at 15:48 +0000, Bart Van Assche wrote: > On Fri, 2018-04-27 at 09:39 -0600, Jens Axboe wrote: > > blk_mq_tagset_busy_iter(&shost->tag_set, scsi_host_check_in_flight, > > &in_flight); > > return in_flight.cnt + atomic_read(&shost->host_busy); > > > > The atomic read is basically free, once we get rid of the dirty of > > that > > variable on each IO. > > Hello Jens, > > What makes you think that " + atomic_read(&shost->host_busy)" is > necessary? > I am not aware of any code outside the SCSI core that modifies the > host_busy > member. > > Thanks, > > Bart. > > > As part of testing latest upstream in MQ and non-MQ I intend to test this patch series fully on actual hardware F/C 8G to memory backed array LUNS and of course SRP/RDMA I have started working on this and will report back. Thanks Laurence
