[libfabric-users] connection-less send/recv with verbs

Ilango, Arun arun.ilango at intel.com
Fri Jul 14 13:23:28 PDT 2017

Hi Maurizio,

Can you try running the test again specifying the verbs interface IP address instead of localhost?

Also please specify a source address arg on the server side (this is not usually required and there is an open issue for this in verbs/RDM provider).


server: fi_rdm_pingpong -p verbs -s <server_verbs_interface_ip_address>
client: fi_rdm_pingpong -p verbs <server_verbs_interface_ip_address>

You can also try using the ofi_rxm provider which provides a connectionless interface to verbs. This is a layered provider which runs over FI_EP_MSG interface of verbs provider.


-----Original Message-----
From: Libfabric-users [mailto:libfabric-users-bounces at lists.openfabrics.org] On Behalf Of Maurizio Drocco
Sent: Friday, July 14, 2017 12:25 PM
To: Hefty, Sean <sean.hefty at intel.com>
Cc: libfabric-users at lists.openfabrics.org
Subject: Re: [libfabric-users] connection-less send/recv with verbs

> Now the problem is that, with the following code:
> ========================================
> ret = fi_send(ep, tx_buf, 32, NULL, to, ctx); assert(!ret);
> while(true) {
> 	ret = fi_cq_read(cq, &comp, 1);
> 	/*…*/
> }
> ========================================
> no completion event is ever found in the queue (always return FI_EAGAIN).
> With gdb, I noticed that the functions used by fi_send and fi_cq_read are, respectively:
> - fi_ibv_rdm_send
> - fi_ibv_rdm_tagged_cq_read
> Do you think there can be some other issue related to modes/capabilities?

Let me add a bit that could help to understand.
I ran some basic tests on the two infiniband clusters I have access to.

The following libfabric test completes successfully:
fi_pingpong -p verbs -e rdm & fi_pingpong -p verbs -e rdm localhost

Whereas the following fabtests test just stalls on the first call to fi_cq_read (in the very same manner as my code):
fi_rdm_pingpong -p verbs & fi_rdm_pingpong -p verbs localhost

I am getting confused :)


Maurizio Drocco
PhD Candidate
University of Torino, department of Computer Science Via Pessinetto 12, 10149 Torino - Italy _______________________________________________
Libfabric-users mailing list
Libfabric-users at lists.openfabrics.org

More information about the Libfabric-users mailing list