linux-kernel - Re: CFQ Idle class slowing down everything?

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] [day] [month] [year] [list]

Date:	Wed, 29 Oct 2008 06:00:34 -0400
From:	Thomas Guyot-Sionnest <dermoth@....ca>
To:	linux-kernel@...r.kernel.org
Subject:  Re: CFQ Idle class slowing down everything?

On 28/10/08 02:07 PM, Phillip Susi wrote:
> Thomas Guyot-Sionnest wrote:
>> On 14/10/08 03:18 PM, Andrew Morton wrote:
>>>> When "idle", the slave do mostly random writes: about 15 rtps and 200
>>>> wtps. For testing I ended up running dd to read files from disk to
>>>> /dev/null while avoiding the system cache (had 42GB of data to read
> 
> Just thought I would point out that dd is, in fact, dirtying the buffer
> cache since you don't pass flag=direct.
> 

Yes, I know that, though at each run I read a different chunk so it
shouldn't affect my benchmark.

The point to note is that even though the CFQ Idle class seems to work
now (it does reduce the IO load instead of making overall IO a lot
slower), it's sill having more impact on my system than using the
deadline scheduler which has no class at all.

--
Thomas

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/