Re: [PATCH] readahead: initial method - expected read size - fix fastcall

Voluspa
2006-06-08T10:05:16Z

On Thu, 8 Jun 2006 16:50:55 +0800 Fengguang Wu wrote:
> On Thu, Jun 08, 2006 at 10:28:02AM +0200, Voluspa wrote:
> > On Thu, 8 Jun 2006 16:13:52 +0800 Fengguang Wu wrote:
> > > It's interesting that copying of sparse file is more efficient with small
> > > readahead size :) I get the same conclusion, though with smaller differences:
> >
> > How on earth can you copy the file without overwriting the target /dev/null?
>
> Yes, it worked as expected. All the time.
>
> I'm running zsh, though bash is also tested ok.
>
> % cp --version
> cp (GNU coreutils) 5.96
> Copyright (C) 2006 Free Software Foundation, Inc.

root:sleipner:~# dd if=/dev/zero of=sparse bs=1M seek=5000 count=1
1+0 records in
1+0 records out
root:sleipner:~# time cp sparse /dev/null
cp: overwrite `/dev/null'? n

root:sleipner:~# cp --version
cp (coreutils) 5.2.1
Written by Torbjorn Granlund, David MacKenzie, and Jim Meyering.

Copyright (C) 2004 Free Software Foundation, Inc.
[etc...]

Ok, guess it's time to build a more modern system. Was planning to do it
anyway. I don't like just updating something like coreutils...

Mvh
Mats Johannesson
--