On Thu, Aug 14, 2025 at 04:22:27PM +0800, Yu Kuai wrote: > Hi, > > 在 2025/08/14 15:54, Ming Lei 写道: > > On Thu, Aug 14, 2025 at 11:35:06AM +0800, Yu Kuai wrote: > > > From: Yu Kuai <yukuai3@xxxxxxxxxx> > > > > > > Backgroud and motivation: > > > > > > At first, we test a performance regression from 5.10 to 6.6 in > > > downstream kernel(described in patch 13), the regression is related to > > > async_depth in mq-dealine. > > > > > > While trying to fix this regression, Bart suggests add a new attribute > > > to request_queue, and I think this is a good idea because all elevators > > > have similar logical, however only mq-deadline allow user to configure > > > async_depth. And this is patch 9-16, where the performance problem is > > > fixed in patch 13; > > > > > > Because async_depth is related to nr_requests, while reviewing related > > > code, patch 2-7 are cleanups and fixes to nr_reqeusts. > > > > > > I was planning to send this set for the next merge window, however, > > > during test I found the last block pr(6.17-rc1) introduce a regression > > > if nr_reqeusts grows, exit elevator will panic, and I fix this by > > > patch 1,8. > > > > Please split the patchset into two: > > > > - one is for fixing recent regression on updating 'nr_requests', so this > > can be merged to v6.17, and be backport easily for stable & downstream > > There are actually two regressions, as fixed by patch 5 and patch 8, how > about the first patchset for patch 1-8? Are you good with those minor > prep cleanup patches? Then probably you need to make it into three by adding one extra bug fix for `fix elevator depth_updated method`, which follows the philosophy of "do one thing, do it better", also helps people to review. Thanks, Ming
