Date: Fri, 16 Apr 2004 18:17:50 -0500 From: Jon Noack <noackjr@alumni.rice.edu> To: Aaron Seelye <aseelye-lists@eltopia.com> Cc: "Jim C. Nasby" <jim@nasby.net> Subject: Re: command piped into bzip not using all available CPU Message-ID: <4080699E.9060307@alumni.rice.edu> In-Reply-To: <002701c42404$e9dbecf0$3102a8c0@metallus> References: <20040416220556.GL87362@nasby.net> <002701c42404$e9dbecf0$3102a8c0@metallus>
next in thread | previous in thread | raw e-mail | index | archive | help
On 4/16/2004 5:48 PM, Aaron Seelye wrote:
> I would venture a guess that bzip is not multi threaded and therefore
> isn't spreading the load around.
I think you may be right. I tested this on my dual Pentium III 933
running 5.2.1-RELEASE-p5. bzip2 behaves like this while gzip behaves as
expected. I know top sucks for measuring performance, but it should be
accurate enough for the big picture.
Here's the simple test with bzip2 (the rand() is to give perl "work"):
perl -e 'do{print rand();}while 1' | bzip2 > /dev/null
**********************************************************************
last pid: 83786; load averages: 0.53, 0.31, 0.19 up 4+03:06:50
17:54:52
92 processes: 2 running, 90 sleeping
CPU states: 52.0% user, 0.0% nice, 11.1% system, 0.4% interrupt, 36.5%
idle
Mem: 222M Active, 154M Inact, 99M Wired, 22M Cache, 60M Buf, 2140K Free
Swap: 1024M Total, 176K Used, 1024M Free
PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU CPU COMMAND
83784 noackjr 106 0 8804K 7280K CPU0 0 0:22 60.19% 49.76% bzip2
83783 noackjr -8 0 2756K 1908K pipdwt 0 0:14 38.87% 32.13% perl
**********************************************************************
This time with gzip (with -9 to make gzip work harder):
perl -e 'do{print rand();}while 1' | gzip -9 > /dev/null
**********************************************************************
last pid: 83865; load averages: 1.11, 0.41, 0.28 up 4+03:18:11
18:06:13
91 processes: 4 running, 87 sleeping
CPU states: 90.7% user, 0.0% nice, 1.6% system, 0.0% interrupt, 7.7%
idle
Mem: 215M Active, 155M Inact, 99M Wired, 19M Cache, 60M Buf, 10M Free
Swap: 1024M Total, 176K Used, 1024M Free
PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU CPU COMMAND
83864 noackjr 117 0 2756K 1908K CPU0 0 0:32 88.37% 73.05% perl
83865 noackjr 116 0 1696K 960K RUN 0 0:30 84.65% 69.97% gzip
**********************************************************************
On a moderately-related note, -CURRENT recently got some pipe updates
(up to 75% bandwidth increase on i386):
http://lists.freebsd.org/pipermail/cvs-src/2004-March/021197.html
Jon Noack
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4080699E.9060307>