On Tue, Sep 19 2017 at 11:36am -0400, Bart Van Assche <Bart.VanAssche@xxxxxxx> wrote: > On Tue, 2017-09-19 at 13:43 +0800, Ming Lei wrote: > > On Mon, Sep 18, 2017 at 03:18:16PM +0000, Bart Van Assche wrote: > > > If you are still looking at removing the blk_mq_delay_run_hw_queue() calls > > > then I think you are looking in the wrong direction. What kind of problem > > > are you trying to solve? Is it perhaps that there can be a delay between > > > > Actually the improvement on dm-rq IO schedule(the patch 2 ~ 5) doesn't > > need this patch. > > The approach of this patch series looks wrong to me and patch 5/5 is an ugly > hack in my opinion. That's why I asked you to drop the entire patch series and > to test whether inserting a queue run call into the dm-mpath end_io callback > yields a similar performance improvement to the patches you posted. Please do > not expect me to spend more time on this patch series if you do not come up > with measurement results for the proposed alternative. Bart, asserting that Ming's work is a hack doesn't help your apparent goal of deligitimizing Ming's work. Nor does it take away from the fact that your indecision on appropriate timeouts (let alone ability to defend and/or explain them) validates Ming calling them into question (which you are now dodging regularly). But please don't take this feedback and shut-down. Instead please work together more constructively. This doesn't need to be adversarial! I am at a loss for why there is such animosity from your end Bart. Please dial it back. It is just a distraction that fosters needless in-fighting. Believe it or not: Ming is just trying to improve the code because he has a testbed that is showing fairly abysmal performance with dm-mq multipath (on lpfc with scsi-mq). Ming, if you can: please see if what Bart has proposed (instead: run queue at end_io) helps. Though I don't yet see why that should be needed. Mike
