Open MPI
My new favorite Open MPI mpirun feature: tab completion
2 min read
Today’s guest author is Nathan Hjelm, a Scientist 2 at Los Alamos National Laboratory. We recently added scripts to support tab completion of mpirun flags and run-time MCA configuration variables to the Open MPI trunk development. The scripts support both bash and zsh and have a number of useful features (depending on the shell). Can’t […]
Speaking at Lawrence Berkeley National Lab next week
1 min read
Are you in the Northern California Bay Area and want to hear about Open MPI and/or Cisco’s usNIC technology next week? If so, you’re in luck! I’ll be speaking at Lawrence Berkeley Lab (LBL) next Thursday, November 7, 2013, at 2:30pm. Click through to see the location and directions and whatnot (LBL requests that you […]
EuroMPI’13 Cisco slides: Open MPI Process Affinity User Interface
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 […]
Short message latency and NUMA effects
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 […]
Ultra low latency Ethernet (UCS “usNIC”): questions and answers
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.
Open MPI and the MPI-3 MPI_T interface
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 […]
Cisco’s Philosophy on Open Source
1 min read
Last weekend, I was fortunate enough to be able to attend the Midwest Open Source Software Conference (MOSSCon 2013). I met some fascinating people, listened to some great talks, and learned a bunch of new things. All in all, a win. I also presented a talk on two things: The general open source philosophy at […]
MPI and Java: redux
1 min read
In a prior blog entry, I discussed how we are resurrecting a Java interface for MPI in the upcoming v1.7 release of Open MPI. Some users have already experimented with this interface and found it lacking, in at least two ways: Creating datatypes of multi-dimensional arrays doesn’t work because of how Java handles them internally […]
Cisco @SC2012
1 min read
Going to Salt Lake City for Supercomputing 2012 next week? So are we! Be sure to drop by and see us in the Cisco booth (#2517). I’ll be there, demonstrating and talking about our latest developments in ultra low latency Ethernet (hint: it includes 250ns port-to-port Ethernet switch latency and our latest MPI/OS-bypass technology on the […]