diskstat 0.1: simple tool to study io patterns via relayfs

diskstat 0.1: simple tool to study io patterns via relayfs

[bert hubert]

It is with distinct lack of pride that I release version 0.1 of diskstat
'Geeks in Black Thorn', a tool that allows you to generate the kinds of
graphs as presented in my OLS talk 'On faster application startup times:
Cache stuffing, seek profiling, adaptive preloading'. The lack of pride is
because this release is more a promise of what is to come than how things
should be.

The presentation, paper, and software can be found on
http://ds9a.nl/diskstat and
http://ds9a.nl/diskstat/diskstat-0.1.tar.gz

>From the README:
The quality of this code is abysmal, for which I squarely blame the fun
people at OLS who've been keeping me from my code!
(...)
The next version will be based on k/jprobes, and will make better use of
relayfs features. This also means you won't have to patch your kernel
anymore, as long as you compiled with kprobes support.

Sample command lines:
   # mkdir /relay
   # mount -t relayfs none /relay
   # ./dumpdiskstat /relay/diskstat0  > dump

   This will output something like:
   I think we skipped at 90867, ret=0
   I think we hit end at 143016, ret=-1
   I think we hit the break again 90867, ret=0

 Process the stats.
   $ ./dswalk < dump

   It will print out huge latencies encountered:

>  Large latency 163.352 on line 14146
   Total read started: 33888768, total ended: 33888768
   Total write started: 1372160, total ended: 1372160
   Waiting time: 10.695 seconds

 Make pretty plots
   gnuplot
   plot 'startplaces.dat', 'headplaces.dat'
   plot 'inflight.dat'

Continue reading on http://ds9a.nl/diskstat/README

-- 
http://www.PowerDNS.com      Open source, database driven DNS Software 
http://netherlabs.nl              Open and Closed source services

Re: diskstat 0.1: simple tool to study io patterns via relayfs

[Sonny Rao]

On Sun, Jul 24, 2005 at 03:07:30AM +0200, bert hubert wrote:
> It is with distinct lack of pride that I release version 0.1 of diskstat
> 'Geeks in Black Thorn', a tool that allows you to generate the kinds of
> graphs as presented in my OLS talk 'On faster application startup times:
> Cache stuffing, seek profiling, adaptive preloading'. The lack of pride is
> because this release is more a promise of what is to come than how things
> should be.
> 
> The presentation, paper, and software can be found on
> http://ds9a.nl/diskstat and
> http://ds9a.nl/diskstat/diskstat-0.1.tar.gz
> 
> >From the README:
> The quality of this code is abysmal, for which I squarely blame the fun
> people at OLS who've been keeping me from my code!
> (...)
> The next version will be based on k/jprobes, and will make better use of
> relayfs features. This also means you won't have to patch your kernel
> anymore, as long as you compiled with kprobes support.

Hi, I had some trouble compiling it, I figured out that one needs
libboost, but then I've also discovered that g++-3.4.4 and g++-4.0.1
don't want to compile it while g++-3.3.5 works.  (FYI, all of these were
Ubuntu versions)

You might want to document some of this in the README :)

Thanks,
Sonny

Re: diskstat 0.1: simple tool to study io patterns via relayfs

[bert hubert]

On Mon, Jul 25, 2005 at 03:56:48AM -0400, Sonny Rao wrote:
> Hi, I had some trouble compiling it, I figured out that one needs
> libboost, but then I've also discovered that g++-3.4.4 and g++-4.0.1
> don't want to compile it while g++-3.3.5 works.  (FYI, all of these were
> Ubuntu versions)

Yes, you are right. I'll fix the Boost thing, but it really should compile
using all those gcc's. Would you mind sending me the errors you get with the
other compilers (privately)?

> You might want to document some of this in the README :)

This is the least of what needs fixing hehe. Thanks.

-- 
http://www.PowerDNS.com      Open source, database driven DNS Software 
http://netherlabs.nl              Open and Closed source services