From mboxrd@z Thu Jan  1 00:00:00 1970
From: Chris Mason <mason@suse.com>
Subject: Re: Horrible ftruncate performance
Date: 11 Jul 2003 10:27:04 -0400
Message-ID: <1057933624.13313.60.camel@tiny.suse.com>
References: <Pine.LNX.4.30.0307100523110.24356-100000@divine.city.tvnet.hu>
	 <20030710052931.GA17957@namesys.com>
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Return-path: <reiserfs-list-return-14882-reiserfs=m.gmane.org@namesys.com>
list-help: <mailto:reiserfs-list-help@namesys.com>
list-unsubscribe: <mailto:reiserfs-list-unsubscribe@namesys.com>
list-post: <mailto:reiserfs-list@namesys.com>
Errors-To: flx@namesys.com
In-Reply-To: <20030710052931.GA17957@namesys.com>
List-Id: <reiserfs-devel.vger.kernel.org>
Content-Type: text/plain; charset="us-ascii"
To: Oleg Drokin <green@namesys.com>
Cc: Szakacsits Szabolcs <szaka@sienet.hu>, reiserfs-list@namesys.com

On Thu, 2003-07-10 at 01:29, Oleg Drokin wrote:
> Hello!
> 
> On Thu, Jul 10, 2003 at 05:23:39AM +0200, Szakacsits Szabolcs wrote:
> 
> > I've noticed very long "hangs" using reiserfs and they were always at
> > ftruncate(2). I made a comparision between different filesystems. SuSE 8.2
> 
> Yes, this is known "feature".
> 
> > (same bad performance on older SuSE versions as well), same partitition,
> > default mkfs.*. Let's create a 200GB sparse file:
> > 	dd if=/dev/zero of=sparse bs=1 seek=200G count=1
> > Results:
> > 	ext3	    0.00 sec
> > 	XFS         0.00 sec
> > 	JFS         0.00 sec
> > 	reiserfs  874.27 sec (all spent in the kernel)
> 
> See the patch below.
> It is merged into 2.4.22-pre3
> Speeds up large holes creation in ~ 1000 times (on 4k blocksize)
> 
> > Is there a faster way to create big sparse files on reiserfs?
> 
> Use the patch. (should apply to 2.4.18,2.4.19,2.4.20,2.4.21)
> (I am unsure if you can apply it to the kernel from SuSE 8.2, though).

I'll try to get this in for 8.3, it makes a huge difference.

-chris