[dm-devel] [PATCH v3 0/7] per-cpu in_flight counters for bio-based drivers

[Jens Axboe]

On 12/5/18 1:24 PM, Mike Snitzer wrote:
> Hi,
> 
> This v3 adds "block: stop passing 'cpu' to all percpu stats methods"
> before switching over to percpu counters.

I gave this a shot, with the hope of being able to use it for blk-mq
as well. The tldr is that it's still slower than the tag iteration,
but that isn't a show stopper for a generic implementation. But
unfortunately it fails for queue size results, iostat just shows
0 for the average queue size.

-- 
Jens Axboe