linux-kernel - Re: Switching to MQ by default may generate some bug reports

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: <CACVXFVP3M64ebQQM-aaBs8-TKFqkgVCvO2TQbB6xLcp9_5Q3Sg@mail.gmail.com>
Date:   Thu, 3 Aug 2017 17:17:21 +0800
From:   Ming Lei <tom.leiming@...il.com>
To:     Mel Gorman <mgorman@...hsingularity.net>
Cc:     Christoph Hellwig <hch@...radead.org>,
        Jens Axboe <axboe@...nel.dk>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        linux-block <linux-block@...r.kernel.org>,
        Paolo Valente <paolo.valente@...aro.org>
Subject: Re: Switching to MQ by default may generate some bug reports

Hi Mel Gorman,

On Thu, Aug 3, 2017 at 4:51 PM, Mel Gorman <mgorman@...hsingularity.net> wrote:
> Hi Christoph,
>
> I know the reasons for switching to MQ by default but just be aware that it's
> not without hazards albeit it the biggest issues I've seen are switching
> CFQ to BFQ. On my home grid, there is some experimental automatic testing
> running every few weeks searching for regressions. Yesterday, it noticed
> that creating some work files for a postgres simulator called pgioperf
> was 38.33% slower and it auto-bisected to the switch to MQ. This is just
> linearly writing two files for testing on another benchmark and is not
> remarkable. The relevant part of the report is

We saw some SCSI-MQ performance issue too, please see if the following
patchset fixes your issue:

http://marc.info/?l=linux-block&m=150151989915776&w=2

Thanks,
Ming