Re: Fwd: Any way to find the network usage by a process?

From: Frank Ch. Eigler
Date: Thu Oct 05 2006 - 17:23:00 EST



Mike Mason <mmlnx@xxxxxxxxxx> writes:

> Here's a variation of Jose's script that uses the networking tapset
> and prints top-like output for transmits and receives. [...]

Thanks for posting it to the systemtap wiki.

Some minor style suggestions follow:

> [...]
> ifxmit_p[pid(), dev_name] ++
> ifxmit_b[pid(), dev_name] += length

These could be collapsed into a single statistics-aggregate array:
# ifxmit[pid(), dev_name] <<< length
Then the printing routine would use @count(ifxmit[...]) and @sum(ifxmit[...])
to extract the two values. Same of course for ifrecv.

> execname[pid()] = execname()
> user[pid()] = uid()
> ifdevs[pid(), dev_name] = dev_name

Calling pid() so many times is worse than calling it once and caching
the result in a local variable ("p = pid()").

The way that the script tracks pid-to-uid and pid-to-execname mappings
is not bad, though if that part were moved to new probes on fork or
exec, it would allow the network-related probes to run concurrently on
an SMP without fighting over locks.


- FChE
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