Phoronix and Hammer - a followup

[Justin Sherrill <justin@xxxxxxxxxxxxxxxxxx>]

A while back, Phoronix published benchmarks for DragonFly 3.0.

http://www.phoronix.com/scan.php?page=news_item&px=MTA3MDA

They showed generally good numbers, but the disk test showed a
startling 250% DROP in disk speed with Hammer between 2.10 and 3.0.
The test is unpacking a certain version of the Linux kernel - pretty
simple test.  That kind of drop would be driving everyone crazy, but I
wanted to put some numbers behind saying "OMG that benchmark for my
favorite operating system is wrong and you are mean!"

There is bug 2288, which shows a small slowdown, but nothing of this magnitude:

http://bugs.dragonflybsd.org/issues/2288

So, I've been running the same test as the Phoronix one, at random
time on shiningsilence.com, before and after upgrading it from
DragonFly 2.10 to DragonFly 3.0.  Here's the command:

/bin/rm -rf linux-2.6.32; /usr/bin/time -o notes.txt -a tar xf
linux-2.6.32.tar.bz2

Here's the results, averaged:

39.791 - 2.10 real 	
28.509 - 2.10 user	
03.529 - 2.10 sys		

44.829 - 3.0 real	
26.137 - 3.0 user	
04.888 - 3.0 sys

There's an ~10ish% increase that's consistent with bug 2288, but
nowhere near what the Phoronix test saw.  Maybe they forgot to remove
the results of unzipping before running the test multiple times?  I
don't know.  Anyway, yes, we do have some sort of slowdown between
2.10 and 3.0, but it's not catastrophic.

Here's the graph cause graphs always make me happy:

<img src="https://docs.google.com/a/shiningsilence.com/spreadsheet/oimg?key=0ArcmL0I6rCOEdDJWclFNOHJSYmVFLVM3V0Jsa0liaUE&oid=2&zx=u2dxp5zd7kn";
/>

And the raw data:

on 2.10
       36.66 real        30.45 user         3.61 sys
       36.69 real        23.96 user         3.02 sys
       43.10 real        28.42 user         3.50 sys
       42.51 real        29.42 user         3.85 sys
       41.16 real        29.84 user         3.64 sys
       36.86 real        28.18 user         3.49 sys
       45.83 real        24.82 user         2.91 sys
       39.05 real        27.60 user         3.57 sys
       39.89 real        29.17 user         3.80 sys
       37.99 real        30.41 user         3.73 sys
       37.94 real        31.01 user         3.89 sys
       39.81 real        28.83 user         3.34 sys
on 3.0
       43.76 real        23.87 user         4.71 sys
       43.46 real        24.26 user         4.04 sys
       42.38 real        26.27 user         4.72 sys
       45.03 real        27.04 user         5.29 sys
       46.22 real        27.78 user         5.51 sys
       46.14 real        24.87 user         4.63 sys
       44.73 real        27.00 user         5.05 sys
       45.28 real        26.07 user         4.57 sys
       47.03 real        27.22 user         4.84 sys
       44.26 real        26.99 user         5.52 sys