Re: 1352 NUL bytes at the end of a page?

From: Steven Cole
Date: Wed May 19 2004 - 09:00:42 EST



On May 19, 2004, at 7:36 AM, Chris Mason wrote:

On Wed, 2004-05-19 at 09:28, Steven Cole wrote:

Steven, with all else being equal, you said you found a 2.6.3 SuSE
kernel to significantly outperform 2.6.6, is that right? If so can
you try the same test with plain 2.6.3 please? We'll go from there.

Actually, it was a Mandrake kernel, 2.6.3-4mdk IIRC. Whatever is
the default with MDK 10. One salient difference with the vendor
kernel is that everything which can be a module is, and I wasn't
using any modules with my kernels. BTW, I was careful to have the
same hdparm settings during the performance testing.

The performance difference was very repeatable. Using the script
provided by Andy Isaacson, the 2.6.3-4mdk did the clone in about
11 minutes total, while the various current kernels took about
15 minutes total. The user times were the same, and the difference
was in system time. Those numbers are from memory, the actual
results should be in the archive.

Was this regression only reiserv3 or both v3 and ext3?

-chris


I went back through the archive to make sure, and since I didn't
specify where I did the timed tests, those timing tests would have
been done on my /home partition, which is reiserfs v3.

Since I was using different partitions for ext3 and reiserfs on
/dev/hda, a direct comparison between ext3 and reiserfs wouldn't
be completely fair, but a "watching the paint dry" observation
seemed to indicate that reiserfs was significantly faster for this
load. I did press my backup disk into service for this testing,
to eliminate the possibility that this was due to a finicky disk,
and I have a 3.9 G partition which I've formatted first reiserfs,
then ext3, so I could do some fair tests between reiserfs and
ext3 on that disk. But I think the results are already known;
reiserfs opens a can of whoopass for this kind of load.

Steven

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