Re: High TLB shootdown I interrupts with wm gigabit NIC?

["Steven M. Bellovin" <smb%cs.columbia.edu@localhost>]

On Tue, 29 Jul 2008 21:21:46 +0100
Mark Cullen <mark.r.cullen%gmail.com@localhost> wrote:

> I just got a Intel Pro/1000 PT PCI-E NIC and am pleased that it
> actually seems to be working. However, I would just like to check if
> the following is considered normal.
> 
> Firstly, transfer rates are "only" about 30MB/s, both with Samba and
> by FTP. This is in both directions. This seems a bit low?

It sounds a bit low, but my network tests have been with
pkgsrc/benchmarks/ttcp.  On some of my machines, I can get very high
throughput with ttcp, but not all; I suspect that the limiting factor
is the machine's backplane or something else in its architecture.
> 
> Secondly, I have noticed that whilst idle "TLB shootdown I" (there
> are two of these, dual core, I believe this is the one for CPU #1) is
> next to nothing. It'll go up to 5 every so often and then just not
> register for the rest of the time. Whilst doing an FTP... it  goes
> through the roof:
> 

Can't help on that one.


                --Steve Bellovin, http://www.cs.columbia.edu/~smb