linux-kernel - Re: huge improvement with per-device dirty throttling

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]

Message-ID: <351207.28447.qm@web32602.mail.mud.yahoo.com>
Date:	Thu, 6 Sep 2007 02:50:10 -0700 (PDT)
From:	Martin Knoblauch <spamtrap@...bisoft.de>
To:	Leroy van Logchem <leroy.vanlogchem@...elft.nl>,
	linux-kernel@...r.kernel.org
Cc:	linux-mm@...ck.org, Peter zijlstra <a.p.zijlstra@...llo.nl>
Subject: Re: huge improvement with per-device dirty throttling


--- Martin Knoblauch <knobi@...bisoft.de> wrote:

> 
> --- Leroy van Logchem <leroy.vanlogchem@...elft.nl> wrote:
> 
> > Andrea Arcangeli wrote:
> > > On Wed, Aug 22, 2007 at 01:05:13PM +0200, Andi Kleen wrote:
> > >> Ok perhaps the new adaptive dirty limits helps your single disk
> > >> a lot too. But your improvements seem to be more "collateral
> > damage" @)
> > >>
> > >> But if that was true it might be enough to just change the dirty
> > limits
> > >> to get the same effect on your system. You might want to play
> with
> > >> /proc/sys/vm/dirty_*
> > > 
> > > The adaptive dirty limit is per task so it can't be reproduced
> with
> > > global sysctl. It made quite some difference when I researched
> into
> > it
> > > in function of time. This isn't in function of time but it
> > certainly
> > > makes a lot of difference too, actually it's the most important
> > part
> > > of the patchset for most people, the rest is for the corner cases
> > that
> > > aren't handled right currently (writing to a slow device with
> > > writeback cache has always been hanging the whole thing).
> > 
> > 
> > Self-tuning > static sysctl's. The last years we needed to use very
> 
> > small values for dirty_ratio and dirty_background_ratio to soften
> the
> > 
> > latency problems we have during sustained writes. Imo these patches
> 
> > really help in many cases, please commit to mainline.
> > 
> > -- 
> > Leroy
> > 
> 
>  while it helps in some situations, I did some tests today with
> 2.6.22.6+bdi-v9 (Peter was so kind) which seem to indicate that it
> hurts NFS writes. Anyone seen similar effects?
> 
>  Otherwise I would just second your request. It definitely helps the
> problematic performance of my CCISS based RAID5 volume.
> 

 please disregard my comment about NFS write performance. What I have
seen is caused by some other stuff I am toying with.

 So, I second your request to push this forward.

Martin

------------------------------------------------------
Martin Knoblauch
email: k n o b i AT knobisoft DOT de
www:   http://www.knobisoft.de
-
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/