linux-kernel - Re: [PATCH RFC md-6.16 v3 15/19] md/md-llbitmap: implement APIs to dirty bits and clear bits

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: <20250514051747.GA24503@lst.de>
Date: Wed, 14 May 2025 07:17:47 +0200
From: Christoph Hellwig <hch@....de>
To: Yu Kuai <yukuai1@...weicloud.com>
Cc: Christoph Hellwig <hch@....de>, xni@...hat.com, colyli@...nel.org,
	agk@...hat.com, snitzer@...nel.org, mpatocka@...hat.com,
	song@...nel.org, linux-kernel@...r.kernel.org,
	dm-devel@...ts.linux.dev, linux-raid@...r.kernel.org,
	yi.zhang@...wei.com, yangerkun@...wei.com, johnny.chenyi@...wei.com,
	"yukuai (C)" <yukuai3@...wei.com>
Subject: Re: [PATCH RFC md-6.16 v3 15/19] md/md-llbitmap: implement APIs to
 dirty bits and clear bits

On Tue, May 13, 2025 at 05:32:13PM +0800, Yu Kuai wrote:
> I was thinking about record a stack dev depth in mddev to handle the
> weird case inside raid. Is there other stack device have the same
> problem? AFAIK, some dm targets like dm-crypt are using workqueue
> to handle all IO.

I guess anything that might have to read in metadata to serve a
data I/O.  bcache, dm-snapshot and dm-thinkp would be candidates for
that, but I haven't checked the implementation.

> I'm still interested because this can improve first write latency.
>
>>
>> So instead just write a comment documenting why you switch to a
>> different stack using the workqueue.
>
> Ok, I'll add comment if we keep using the workqueue.

Maybe do that for getting the new bitmap code in ASAP and then
revisit the above separately?