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Re: Boot poster challenge



On Sat, 2004-11-20 at 18:47 +0100, Arjan van de Ven wrote: 
> > Yeah I guess the fact that disk caches are loaded on a per-file basis
> > doesn't help either.  Because in theory: stat-ing your list takes about
> > 3 sec and readahead on a tarball is instantaneous (both of course
> > without boot-time readahead).
> 
> ok here is another try; I hacked up a tool to sort the list in disk
> order.

Arjan,

not quite the improvement I expected, but it does shave off an
additional 2 seconds:
http://www.klika.si/ziga/bootchart/bootchart-sortreadahead.png

This chart includes data from iostat (sysstat package).  Notice how the
disk is fully utilized (%util) during readahead, but the throughput
(rkB/s) is *really* low.  This could very well be a problem with my hard
disk.  hdparm seems fine though (and I checked the parameters before
running readahead).

Let me know if you'd find any other iostat columns useful in the chart.
The log file is here:
http://www.klika.si/ziga/bootchart/boot.io.log.sortreadahead.gz


Anyway, the bootchart scripts and source code will be on SourceForge
tomorrow so people will be able to post their results.

Thanks,
-- 
Ziga


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