Re: [PATCH] block: check more requests for multiple_queues in blk_attempt_plug_merge
From: Paul Menzel <hidden>
Date: 2022-03-11 22:43:37
Also in:
linux-block, stable
Dear Song, Am 11.03.22 um 17:59 schrieb Song Liu:
On Fri, Mar 11, 2022 at 6:16 AM Jens Axboe [off-list ref] wrote:quoted
On 3/10/22 5:07 PM, Jens Axboe wrote:quoted
In any case, just doing larger reads would likely help quite a bit, but would still be nice to get to the bottom of why we're not seeing the level of merging we expect.Song, can you try this one? It'll do the dispatch in a somewhat saner fashion, bundling identical queues. And we'll keep iterating the plug list for a merge if we have multiple disks, until we've seen a queue match and checked.This one works great! We are seeing 99% read request merge and 500kB+ average read size. The original patch in this thread only got 88% and 34kB for these two metrics.
Nice. I am curious, how these metrics can be obtained? […] Kind regards, Paul