Hi Zack, On 29 September 2010 at 18:22, Zack Weinberg wrote: | Package: r-cran-rmpi | Version: 0.5-8-2 | Severity: normal | | Upon | | > library(snow) | > cl = makeCluster(7, type="MPI") | | (on an 8-core machine), CPU utilization jumps *immediately* from 98% idle | to 20% user, 70% system, 12% idle. strace reveals that each slave is | spinning through poll() calls with timeout zero, rather than blocking | until a message arrives, as the documentation for mpi.probe() suggests | should happen. | | I suppose this might be a problem in libopenmpi instead of the R binding, | I haven't tried to reproduce it with anything lower-level.
Very much so. It is "permanent polling" in Open MPI that does that --- and Rmpi can do little about it. So I think after some discussion we may want to reassign or close this. I used to be a little closer to Open MPI development (but now Manuel does such wonderful work that I could step back from this :-) and there once was word of changing. Manuel, any idea if that happened? Wasn't Open MPI 1.4 supposed to take care of this? Is there a new option? Dirk | | -- System Information: | Debian Release: squeeze/sid | APT prefers unstable | APT policy: (500, 'unstable'), (101, 'experimental') | Architecture: amd64 (x86_64) | | Kernel: Linux 2.6.35-trunk-amd64 (SMP w/8 CPU cores) | Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8) | Shell: /bin/sh linked to /bin/dash | | Versions of packages r-cran-rmpi depends on: | ii libc6 2.11.2-6 Embedded GNU C Library: Shared lib | ii libopenmpi1.3 1.4.2-4 high performance message passing l | ii mpi-default-bin 0.6 Standard MPI runtime programs | ii r-base-core 2.11.1-6 GNU R core of statistical computat New R 2.12.0 builds in experimental by the way. I run those too. 2.12 will come on October 15. | | r-cran-rmpi recommends no packages. | | Versions of packages r-cran-rmpi suggests: | ii r-cran-rsprng 1.0-1 GNU R interface to SPRNG (Scalable | | -- no debconf information | | -- Dirk Eddelbuettel | e...@debian.org | http://dirk.eddelbuettel.com -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
