Coda File System

venus/kernel profiling/speed

From: Troy Benjegerdes <>
Date: Thu, 15 Jul 2004 10:53:39 -0500
Has anyone looked at why something like 'tar jxvf linux-2.6.7.tar.bz2' is
so slow, even in disconnected mode?

I could potentially understand, if I was hitting the disk all the time,
but my laptop has a gig of ram, and currently has 128MB free.

I've gotten used to be able to build random source packages out of AFS
without a huge performance hit.. it is obviously slower than local, but
not enough that I want to give up not having to worry about what machine
I built and modified package XXX on.

I guess my rule of thumb is "if it takes less than 5 minutes I don't
care how inefficient it is", and extracting the kernel is defintely
taking longer than 5 minutes.

I suppose part of it is data coming from kernel -> venus -> kernel ->
disk. Can we find a way to short-circuit the common case so the bulk
file data doesn't have to go through copy_{to|from}_user in the kernel?

Troy Benjegerdes                'da hozer'        

Somone asked my why I work on this free (
software stuff and not get a real job. Charles Shultz had the best answer:

"Why do musicians compose symphonies and poets write poems? They do it
because life wouldn't have any meaning for them if they didn't. That's why
I draw cartoons. It's my life." -- Charles Shultz
Received on 2004-07-15 11:56:55