linux-kernel - Re: [PATCH 00/16] blk-mq: introduce new queue attribute asyc

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aJ2WH_RAMPQ9sd6r@fedora>
Date: Thu, 14 Aug 2025 15:54:07 +0800
From: Ming Lei <ming.lei@...hat.com>
To: Yu Kuai <yukuai1@...weicloud.com>
Cc: axboe@...nel.dk, yukuai3@...wei.com, bvanassche@....org,
	nilay@...ux.ibm.com, hare@...e.de, linux-block@...r.kernel.org,
	linux-kernel@...r.kernel.org, yi.zhang@...wei.com,
	yangerkun@...wei.com, johnny.chenyi@...wei.com
Subject: Re: [PATCH 00/16] blk-mq: introduce new queue attribute asyc_dpeth

On Thu, Aug 14, 2025 at 11:35:06AM +0800, Yu Kuai wrote:
> From: Yu Kuai <yukuai3@...wei.com>
> 
> 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

- another one is for improving IO performance related with async_depth.


Thanks,
Ming