Re: [tbench regression fixes]: digging out smelly deadmen.

From: Ilpo Järvinen
Date: Fri Oct 31 2008 - 07:15:30 EST


On Fri, 31 Oct 2008, Eric Dumazet wrote:

> Ilpo Järvinen a écrit :
> > On Fri, 31 Oct 2008, Eric Dumazet wrote:
> >
> > > David Miller a écrit :
> > > > From: "Ilpo Järvinen" <ilpo.jarvinen@xxxxxxxxxxx>
> > > > Date: Fri, 31 Oct 2008 11:40:16 +0200 (EET)
> > > > > > Let me remind that it is just a single process, so no ping-pong
> >> & other
> > > > > lock related cache effects should play any significant role here,
> > > no? (I'm
> > > > > no expert though :-)).
> > > > > Not locks or ping-pongs perhaps, I guess. So it just sends and
> > > > receives over a socket, implementing both ends of the communication
> > > > in the same process?
> > > > > If hash chain conflicts do happen for those 2 sockets, just
> > > traversing
> > > > the chain 2 entries deep could show up.
> > >
> > > tbench is very sensible to cache line ping-pongs (on SMP machines of
> > > course)
> >
> > ...Sorry to disappoint you but we were discussion there on my AIM9 tcp_test
> > results :-).
> >
>
> Well, before you added AIM9 on this topic, we were focusing on tbench :)
>
> Sorry to disappoint you :)

It's all Stephen's fault, he added port randomization first... ;-)

--
i.