Re: all syscalls initially taking 4usec on a P4? Re: nonblocking UDPv4 recvfrom() taking 4usec @ 3GHz?

On Tue, Feb 20, 2007 at 02:02:00PM -0800, Rick Jones wrote:

The slope appears to be flattening-out the farther out to the right it 
goes.  Perhaps that is the length of time it takes to take all the 
requisite cache misses.

The rate of flattening out appears to correlate with the number of processes
running, even though the system is otherwise >99.5% idle during my
measurements.

With only 'gdm' running, things flatten out slowly, iow, it takes longer
delays to see recvfrom slow down. With only 1 process running (init=bash),
the graph is nearly flat.

From this, it is probable that even an idle GNOME desktop (Ubunty Edgy Eft)

is under fierce cache pressure, enough to blow away my meagre 1MB in a
matter of milliseconds.

I'm trying to figure out which processes have the most impact, I had already
killed anything non-essential. But that still leaves 140 pids.

	Bert

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