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List:       reiserfs-devel
Subject:    (reiserfs) Vladimir gets to the bottom of [Fwd: (reiserfs) Is this bad?]
From:       Hans Reiser <reiser () idiom ! com>
Date:       1999-02-08 19:16:45
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I am going to put this into our paper as a concrete example of the possible effects \
of changing our tuning defines. Our project for the future is to get this performance \
without these defines being set, and we are currently exploring changing our key \
allocation algorithm so that we get much of the effect of notails being set. Having \
notails set should ideally only affect memory bandwidth consumption during writes, \
but we currently see a strong effect on reads.
We are also changing file_read so that we get the effect of simple read or complex \
read according to which of them is most optimal.  Actually, we are completing \
rewriting file_read, and then we will benchmark against both settings and see if we \
beat them both at both large reads and small reads.  We know that we can do something \
stupid involving looking at the size of the read and branching to different code \
accordingly, but we hope for better. Currently complex read is best at large reads, \
and reads with lots of locality of reference.

Hans

--
Dump NT! Get Linux (http://www.kernel.org) plus ReiserFS
 (http://devlinux.org/namesys).  If you sell an OS or
internet appliance, buy a port of ReiserFS!
Speed matters.  Trees are fast.  Go faster!


[Attachment #5 (text/html)]

<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
I am going to put this into our paper as a concrete example of the possible
effects of changing our tuning defines.
<br>Our project for the future is to get this performance without these
defines being set,
<br>and we are currently exploring changing our key allocation algorithm
so that we get much of the effect of notails being set.
<br>Having notails set should ideally only affect memory bandwidth consumption
during writes, but we currently see a strong
<br>effect on reads.
<br>We are also changing file_read so that we get the effect of simple
read or complex read according to which of
<br>them is most optimal.&nbsp; Actually, we are completing rewriting file_read,
and then we will benchmark against both
<br>settings and see if we beat them both at both large reads and small
reads.&nbsp; We know that we can do something
<br>stupid involving looking at the size of the read and branching to different
code accordingly, but we hope for better.
<br>Currently complex read is best at large reads, and reads with lots
of locality of reference.
<p>Hans
<pre>--&nbsp;
Dump NT! Get Linux (<A HREF="http://www.kernel.org">http://www.kernel.org</A>) plus ReiserFS
&nbsp;(<A HREF="http://devlinux.org/namesys">http://devlinux.org/namesys</A>).&nbsp; If you sell an OS or
internet appliance, buy a port of ReiserFS!
Speed matters.&nbsp; Trees are fast.&nbsp; Go faster!</pre>
&nbsp;</html>


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Date: Mon, 08 Feb 1999 18:12:58 +0300
From: "Vladimir V. Saveliev" <vs@namesys.botik.ru>
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To: Shawn Leas <sleas@ixion.honeywell.com>, Hans Reiser <reiser@idiom.com>
Subject: Re: (reiserfs) Is this bad?
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Shawn Leas wrote:

> I just did a quick measure, and want an opinion: Where is
> the bottleneck?
> 
> EXT2:   tar zxvf glibc-2.1.tar.gz  6.80s user 5.21s system 48% cpu 24.542 total
> REISER: tar zxvf glibc-2.1.tar.gz  7.55s user 10.09s system 28% cpu 1:01.90 total
> 
> -Shawn
> <=========== America Held Hostage ===========>
> Day 2209 for the poor and the middle class.
> Day 2228 for the rich and the dead.
> 713 days remaining in the Raw Deal.
> <============================================>

Hello
There are few variants of reiserfs. We still did not decide what of them is the main \
one. In this test, default configuration of reiserfs works bad.

I have changed your test a little:

i=0
while [ $i -lt 10 ]
do
        mkdir $i
        cd $i
        time tar zxf ../glibc_2.0.7t.orig.tar.gz
        cd ..
        i=$[ $i + 1 ]
done

and repeated it for the configuration that is the fastest one. It is not the default \
because we did not finish our experiments yet.

I uncommented  #define SIMPLE_READ in include/linux/reiserfs_fs.h,
formatted with 1K block (mkreiserfs -k 1 /dev/...),
mounted with (mount -t reiserfs -o notail,nopreserve /dev/...  /mnt).

Here is the result (elapsed times only):

        ext2fs(1k)    reiserfs
1.    0:07.02        0:06.17
2.    0:10.21        0:06.13
3.    0:07.57        0:07.27
4.    0:08.57        0:07.67
5.    0:07.59        0:06.68
6.    0:09.32        0:06.39
7.    0:08.76        0:06.25
8.    0:09.10        0:08.40
9.    0:08.24        0:09.76
10.   0:09.10        0:09.87

Thanks
vs



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