In the world of high-performance computing, we jump through hoops to extract the last bit of performance from our machines. The vast majority of processes use the Message Passing Interface (MPI) to handle communication. Each MPI implementation abstracts the underlying network away, depending on the available interconnect(s). Ideally, the interconnect offers some form of operating system (OS) bypass and remote memory access in order to provide the lowest possible latency and highest possible throughput. If not, MPI typically falls back to TCP sockets. The MPI’s network abstraction layer (NAL) then optimizes the MPI communication pattern to match that of the interconnect’s API. For similar reasons, most distributed, parallel filesystems such as Lustre, PVFS2, and GPFS, also rely on a NAL to maximize performance. Read More »
Just in case you didn’t see my tweet: my group is hiring!
We need some Linux kernel hackers for some high-performance networking stuff. This includes MPI and other verticals.
I believe that the official job description is still working its way through channels before it appears on the official external Cisco job-posting site, but the gist of it is Linux kernel work for Cisco x86 servers (blades and rack-mount) and NICs in high performance networking scenarios.
Are you interested? If so, send me an email with your resume — I’m jsquyres at cisco dot com.
Here’s a not-uncommon question that we get on the Open MPI mailing list:
Why do MPI processes consume 100% of the CPU when they’re just waiting for incoming messages?
The answer is rather straightforward: because each MPI process polls aggressively for incoming messages (as opposed to blocking and letting the OS wake it up when a new message arrives). Most MPI implementations do this by default, actually.
The reasons why they do this is a little more complicated, but loosely speaking, one reason is that polling helps get the lowest latency possible for short messages.
It’s that time of year again — time to submit EuroMPI 2012 papers!
The conference will be in Vienna, Austria on 23-26 September, 2012. Please come join us! It’s an excellent opportunity to hear how real-world users are actually using MPI, find out about bleeding-edge MPI-based research, and hear what the MPI Forum is up to.
Here’s the official EuroMPI 2012 CFP:
BACKGROUND AND TOPICS
EuroMPI is the preeminent meeting for users, developers and researchers to interact and discuss new developments and applications of message-passing parallel computing, in particular in and related to the Message Passing Interface (MPI). The annual meeting has a long, rich tradition, and the 19th European MPI Users’ Group Meeting will again be a lively forum for discussion of everything related to usage and implementation of MPI and other parallel programming interfaces. Traditionally, the meeting has focused on the efficient implementation of aspects of MPI, typically on high-performance computing platforms, benchmarking and tools for MPI, short-comings and extensions of MPI, parallel I/O and fault tolerance, as well as parallel applications using MPI. The meeting is open towards other topics, in particular application experience and alternative interfaces for high-performance heterogeneous, hybrid, distributed memory systems.
I know we’ve been talking about new MPI-3 things for forever. But this is the last list of new things.
I can say this with certainly because the Forum’s March meeting was the deadline for all new proposals to make it into the MPI-3 standard. Anything else will have to be in MPI-<next> (where <next> may be 3.1, or 4, or …11. Shrug).
Because of the deadline, we had a blizzard of proposals finally get into shape to be presented to the entire Forum. Let’s talk about some of the more interesting ones…