[dm-devel] [PATCH v4 0/7] per-cpu in_flight counters for bio-based drivers

[Jens Axboe]

On Thu, Dec 6, 2018 at 9:41 AM Mike Snitzer <snitzer at redhat.com> wrote:
>
> Hey,
>
> This v4 addresses the compile issues on various archs when CONFIG_SMP
> isn't set (by introducing appropriate wrappers in genhd.h)
>
> Testing with this v4 I was unable to reproduce the issue you reported
> where iostat always reports 0 for avgqu-sz -- but please let me know
> if you still see problems like that.

Looks good to me, and also passes my testing. Dropped the mq special
cases and used this in general, also works fine. I was hoping we could
get rid of the tag iteration with this, but that still seems to be more
efficient for blk-mq. But at least we're better off for stacked devices
with this.

-- 
Jens Axboe