Today’s guest posting comes from Jesper Larsson Träff; he’s Faculty of Informatics, Institute of Information Systems in the Research Group for Parallel Computing at the Vienna University of Technology (TU Wien). Have you ever wondered why MPI is designed the way that it is? The slides below are from Jesper’s talk about the History and Development of […]
A fun scenario was proposed in the MPI Forum today. What do you think this code will do? MPI_Comm comm, save; MPI_Request req; MPI_Init(NULL, NULL); MPI_Comm_dup(MPI_COMM_WORLD, &comm); MPI_Comm_rank(comm, &rank); save = comm; MPI_Isend(smsg, 4194304, MPI_CHAR, rank, 123, comm, &req); MPI_Comm_free(&comm); MPI_Recv(rmsg, 4194304, MPI_CHAR, rank, 123, save, MPI_STATUS_IGNORE);
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 […]
I’ve been a bit remiss about posting recently; it’s conference-paper-writing season, folks — sorry. But I thought I’d mention that I’ll be speaking at the Midwest Open Source Software Convention (MOSSCon) this weekend. I’ll be talking about my work in Open MPI, Hardware Locality (hwloc), and other open source projects, as well as Cisco’s role […]
I’m very pleased to welcome a new member to the Cisco USNIC/MPI Team: Dave Goodell. Welcome, Dave! (today was his first day) Dave joins us from the MPICH team at Mathematics and Computer Science division at Argonne National Laboratory.
I was just recently informed that my talk was accepted at the Midwest Open Source Software Conference (MOSSCon). w00t! MOSSCon will be held at the University of Louisville, in Louisville, Kentucky, USA, on May 18-19, 2013. It’s being organized by people from the Kentucky Open Source Society (KYOSS) and other open source / maker-oriented groups […]
In a prior blog post, I talked about latency analogies. I compared levels of latencies to your home, your neighborhood, a far-away neighborhood, and another city. I talked about these localities in terms of communication. Let’s extend that analogy to talk about data locality.
Multiple readers have told me that it is difficult for them to understand and/or visualize the effects of latency on their HPC applications, particularly in modern NUMA (non-uniform memory access) and NUNA (non-uniform network access) environments. Let’s breaks down the different levels of latency in a typical modern server and network computing environments.
A number of you complained when blogs.cisco.com switched to requiring a social medial login to leave comments. It turns out that you were not alone. Industry-wide, it seems that many people do not want to associate their personal Facebook/Twitter/etc. logins with work-related social media (i.e., this effect was seen at more than just Cisco). The […]
