Re: [Ethereal-users] Large memory footprint

[Guy Harris <guy@xxxxxxxxxx>]

On Thu, Apr 04, 2002 at 04:44:32PM -0800, Chris Robertson wrote:
> A quick question, I'm loading faily large capture files (created with
> tcpdump -w <input.file>, between 100MB-400MB, up to millions packets) into
> Ethereal and I'm getting a memory footprint of 600MB to just under 1GB.  Is
> this normal?

Given that the GTK+ widget Ethereal uses to display the list of packets
allocates a string for *every* column in *every* row, the memory
footprint could be large.  That'd probably take at least 35 or so bytes
per packet for starters.

That widget also allocates a data structure per row, and Ethereal also
allocates a data structure per packet - possibly more than one, in order
to keep state information needed for some protocols.

When you say "up to millions [of] packets", how many are "millions"? 1
million packets?  10 million?  More?

> Also, Ethereal is single threaded, correct?

It's single-threaded except when you do an "Update list of packets in
real time" capture, in which case there's one process doing the
capturing and another process updating the display.

They're not "threads" in the sense of, say, pthreads, but they could run
on different CPUs.

Nothing else uses more than one thread of control; I'm not certain that
there's anything that could make good use of multiple CPUs or, even if
there is, that it wouldn't involve a considerable amount of work to
parallelize.