On Thu, Jan 11 2018 at 6:27pm -0500, Bart Van Assche <Bart.VanAssche@xxxxxxx> wrote: > On Thu, 2018-01-11 at 17:58 -0500, Mike Snitzer wrote: > > The changes are pretty easy to review. This notion that these changes > > are problematic rings very hollow given your lack of actual numbers (or > > some other concerning observation rooted in testing fact) to back up > > your position. > > It's not my job to run the multi-LUN test. That's the job of the people who > want these patches upstream. Since I asked for these test results for the first > time several months ago I'm surprised that nobody has run these tests yet. I've reasoned through a few different ways to respond to this. Fact is you're not giving me much to work with. AFAIK you _are_ charted with supporting the types of storage configs that you've requested performance results from. Your dm-rq.c commit 6077c2d706097c0 ("dm rq: Avoid that request processing stalls sporadically") silently went in through Jens: https://www.redhat.com/archives/dm-devel/2017-April/msg00157.html Not sure why that happened to begin with honestly. But at the end of that post I meant to say: "If this dm-mq specific commit is justified the case certainly is _not_ spelled out in the commit header." Anyway, I've split this contentious removal of dm_mq_queue_rq's blk_mq_delay_run_hw_queue(hctx, 100/*ms*/) into a separate patch; but at this point I'm still inclined to accept it for 4.16. I'll hopefully look closer at understanding the need for commit 6077c2d706097c0 tomorrow. In the meantime, I'd _really_ appreciate it if you'd give the rest of the changes Ming has proposed in this patchset a much more open mind! Thanks, Mike