Jeff Squyres

1 min read

The slides below are from my presentation at EuroMPI’13 about Open MPI’s flexible process affinity interface (in OMPI 1.7.2 and later).  I described this system in a prior blog entries (one, two, three), but many people keep asking me about it. Josh Hursey from U. Wisconsin, LaCrosse, wrote this IMUDI paper about the interface (IMUDI […]

1 min read

A few people asked me to post the slides that I just presented in the Cisco vendor session at EuroMPI’13.  In short, I gave a brief overview of our servers and switches, and then some technical details of how we use SR-IOV in our usNIC, etc. Here’s the slides:

4 min read

In a previous post, I gave some (very) general requirements for how to setup / install an MPI installation. This is post #2 in the series: now that you’ve got a shiny new computational cluster, and you’ve got one or more MPI implementations installed, I’ll talk about how to build, compile, and link applications that […]

4 min read

I often get questions from those who are just starting with MPI; they want to know common things such as: How to install / setup an MPI implementation How to compile their MPI applications How to run their MPI applications How to learn more about MPI This will be the first blog entry of several […]

4 min read

I have previously written a few details about our upcoming ultra low latency solution for High Performance Computing (HPC).  Since my last blog post, a few of you sent me emails asking for more technical details about it. So let’s just put it all out there.

2 min read

I’ve previously written a bunch about the effects of location, Location, LOCATION! on MPI applications. Here’s another subtle NUMA effect that a well-tuned MPI implementation can hide from you: intelligently distributing traffic between multiple network interfaces. Yeah, yeah, most MPI implementations have had so-called “multi-rail” support for a long time (i.e., using multiple network interfaces […]

2 min read

If you’re a bargain basement HPC user, you might well scoff at the idea of having more than one network interface for your MPI traffic. “I’ve got (insert your favorite high bandwidth network name here)! That’s plenty to serve all my cores! Why would I need more than that?” I can think of (at least) […]

3 min read

Open MPI recently revamped its entire run-time parameter system (a.k.a., “MCA parameter system”) as part of its implementation effort for the “MPI_T” interface from MPI-3. The MPI_T interface is a standardized interface designed for MPI tools, but can be used by regular MPI application programs, too. Specifically, MPI_T provides programatic access to two types of […]

2 min read

I’ve previously posted on “Why MPI is Good for You” (blog tag: why-mpi-is-good-for-you).  The short version is that it hides the typical application programmer from lots and lots of underlying network stuff; stuff that they really, really don’t want to be involved in. Here’s another case study… Cisco’s upcoming ultra-low latency MPI transport is implemented […]