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From: Gleb Natapov (glebn_at_[hidden])
Date: 2006-12-04 13:00:06


On Mon, Dec 04, 2006 at 10:53:26PM +0530, Chevchenkovic Chevchenkovic wrote:
> Hi,
> It is not clear from the code as mentioned by you from
> ompi/mca/pml/ob1/ where exactly the selection of BTL bound to a
> particular LID occurs. Could you please specify the file/function name
> for the same?
There is no such code there. OB1 knows nothing about LIDs. It does RR
over all available interconnects. It can do RR between ethernet, IB
and Myrinet for instance. BTL presents each LID as different virtual HCA
to OB1 and it does round-robin between them without event knowing this
is the same port of the same HCA.

Can you explain what are you trying to achieve?

> -chev
>
>
> On 12/4/06, Gleb Natapov <glebn_at_[hidden]> wrote:
> > On Mon, Dec 04, 2006 at 01:07:08AM +0530, Chevchenkovic Chevchenkovic wrote:
> > > Also could you please tell me which part of the openMPI code needs to
> > > be touched so that I can do some modifications in it to incorporate
> > > changes regarding LID selection...
> > >
> > It depend what do you want to do. The part that does RR over all
> > available LIDs is in OB1 PML (ompi/mca/pml/ob1/), but the code doesn't
> > aware of the fact that it is doing RR over different LIDs and not
> > different NICs (yet?).
> >
> > The code that controls what LIDs will be used is in
> > ompi/mca/btl/openib/btl_openib_component.c.
> >
> > > On 12/4/06, Chevchenkovic Chevchenkovic <chevchenkovic_at_[hidden]> wrote:
> > > > Is it possible to control the LID where the send and recvs are
> > > > posted.. on either ends?
> > > >
> > > > On 12/3/06, Gleb Natapov <glebn_at_[hidden]> wrote:
> > > > > On Sun, Dec 03, 2006 at 07:03:33PM +0530, Chevchenkovic Chevchenkovic
> > > > wrote:
> > > > > > Hi,
> > > > > > I had this query. I hope some expert replies to it.
> > > > > > I have 2 nodes connected point-to-point using infiniband cable. There
> > > > > > are multiple LIDs for each of the end node ports.
> > > > > > When I give an MPI_Send, Are the sends are posted on different LIDs
> > > > > > on each of the end nodes OR they are they posted on the same LID?
> > > > > > Awaiting your reply,
> > > > > It depend what version of Open MPI your are using. If you are using
> > > > > trunk or v1.2 beta then all available LIDs are used in RR fashion. The
> > > > early
> > > > > versions don't support LMC.
> > > > >
> > > > > --
> > > > > Gleb.
> > > > > _______________________________________________
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> > > > > users_at_[hidden]
> > > > > http://www.open-mpi.org/mailman/listinfo.cgi/users
> > > > >
> > > >
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> >
> > --
> > Gleb.
> > _______________________________________________
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--
			Gleb.