Hi Jens, On Fri, Mar 11, 2022 at 6:16 AM Jens Axboe <axboe@xxxxxxxxx> wrote: > > On 3/10/22 5:07 PM, Jens Axboe wrote: > > 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. Thanks, Song [...]