Key for high CPU usage

[Leen Besselink]

Daniel.Li wrote:
> Dear List,
> 
> I'm trying to take a closer look at rsync code, and found when we run
> daemon, it will take a lot of CPU (400Mhz). So I'm interested in Which
> part of rsync code on ver 3.0.5 consuming CPU a lot?
> 
> Can anyone here help to lighten me up? So I can try to improve the
> performance or low the CPU usage.
> 
> 
> I suspect that there are a few factors, which might related with CPU
> usage: rolling checksum/Disk IO(a slide window has been implemented),
> read or write?
> 
> 
> Hope I can find some info here! Thanks in advance! 
> 
> 

Hi Daniel,

Not sure how much you know about how rsync works, but maybe you first want
to know how the algoritm works ? I'm fairly sure it's a large part of the
CPU-usage:

http://www.samba.org/rsync/tech_report/

But I personally enjoyed the talk talk Andrew Tridgell did at OLS in 2000
more, here is a transcript:

http://olstrans.sourceforge.net/release/OLS2000-rsync/OLS2000-rsync.html

Here are the slides of the talk:

ftp://ftp.samba.org/pub/tridge/talks/rsync_ols.tgz

I wouldn't be surprised if you were able to find the mp3 online somehere
with the filename:

2000-07-21_15-02-49_C_64.mp3