measuring 2.6.1 improvements

Wayne Davison wayned at
Tue Apr 27 21:49:38 GMT 2004

On Tue, Apr 27, 2004 at 02:14:10PM -0600, Eric Whiting wrote:
> I was watching the memory usage with a bash command line while loop 
> while(true);do cat /proc/$pid/status |grep VmSize ;sleep 60;done

A very nice way to do that.  You might want to watch the VmRSS value,
which will tell you how much of the memory is resident.  A lower RSS
value means it will play nicer with other processes when memory is

> Wayne Davison wrote:
> > If you want to see an even larger improvement, compare the use of
> > the -H option (--hard-link) between versions (and note how much less
> > data is sent over the wire too).
> I'm confused. I don't think I have hard links in this tree. This
> improvement will not help me without hard links will it?

No, it won't help your situation.  If your goal is to fine-tune your
setup, ignore this comment.  If your goal is to measure improvements
in how rsync 2.6.1 handles memory compared to earlier versions, the
improvement when -H is used is very pronounced and worth a look-see.

> Not sure about my fork() -- here is the sys info:
> linux kernel 2.4.21

Linux has copy-on-write memory sharing for fork().  I'm not sure how to
ask /proc for the shared-memory value, though.  I usually use "top" for


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