linux-kernel - Re: [PATCH 00/14] introduce the BFQ-v0 I/O scheduler as an extra scheduler

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: <20161026152955.GA21262@infradead.org>
Date:   Wed, 26 Oct 2016 08:29:55 -0700
From:   Christoph Hellwig <hch@...radead.org>
To:     Arnd Bergmann <arnd@...db.de>
Cc:     Bart Van Assche <bart.vanassche@...disk.com>,
        Jan Kara <jack@...e.cz>, Christoph Hellwig <hch@...radead.org>,
        Paolo Valente <paolo.valente@...aro.org>,
        Jens Axboe <axboe@...nel.dk>, Tejun Heo <tj@...nel.org>,
        linux-block@...r.kernel.org, linux-kernel@...r.kernel.org,
        ulf.hansson@...aro.org, linus.walleij@...aro.org,
        broonie@...nel.org, hare@...e.de, grant.likely@...retlab.ca,
        James.Bottomley@...senpartnership.com
Subject: Re: [PATCH 00/14] introduce the BFQ-v0 I/O scheduler as an extra
 scheduler

On Wed, Oct 26, 2016 at 05:13:07PM +0200, Arnd Bergmann wrote:
> The question to ask first is whether to actually have pluggable
> schedulers on blk-mq at all, or just have one that is meant to
> do the right thing in every case (and possibly can be bypassed
> completely).

That would be my preference.  Have a BFQ-variant for blk-mq as an
option (default to off unless opted in by the driver or user), and
not other scheduler for blk-mq.  Don't bother with bfq for non
blk-mq.  It's not like there is any advantage in the legacy-request
device even for slow devices, except for the option of having I/O
scheduling.