xfs
[Top] [All Lists]

Re: Extreme slowness with xfs [WAS: Re: Slowness with new pc]

To: Martin Steigerwald <Martin@xxxxxxxxxxxx>
Subject: Re: Extreme slowness with xfs [WAS: Re: Slowness with new pc]
From: Dave Chinner <david@xxxxxxxxxxxxx>
Date: Thu, 27 Nov 2008 08:43:08 +1100
Cc: xfs@xxxxxxxxxxx
In-reply-to: <200811261330.27328.Martin@xxxxxxxxxxxx>
Mail-followup-to: Martin Steigerwald <Martin@xxxxxxxxxxxx>, xfs@xxxxxxxxxxx
References: <1226760254.5089.11.camel@chevrolet> <492B5684.2080107@xxxxxxxxxxx> <1227647010.7992.34.camel@chevrolet> <200811261330.27328.Martin@xxxxxxxxxxxx>
User-agent: Mutt/1.5.18 (2008-05-17)
On Wed, Nov 26, 2008 at 01:30:26PM +0100, Martin Steigerwald wrote:
> I wonder whether XFS performance with barriers enabled can be improved? 

Not really. It requires fundamentally altering the way the
transaction system works, and that's no easy task. I have a few
things that I'm looking at, but nothing that would be considered
short-term....

> And whether XFS with disabled write cache (via hdparm) but without 
> barriers might even be *faster* than XFS with barriers... One thing to 
> test eventually.

Yes, it often is with SATA drives - it depends on the quality of
the NCQ implementation in the drive. For SCSI drives, no write
cache or barriers is almost always faster than using WC+barriers.

Cheers,

Dave.
-- 
Dave Chinner
david@xxxxxxxxxxxxx

<Prev in Thread] Current Thread [Next in Thread>