On Fri, Mar 30, 2012 at 8:24 AM, Paul Rosenfeld <[email protected]>wrote:
> Do you think it is very important to have a stripped down kernel? Do you > think having a kernel with more stuff compiled in causes more noise/longer > runtime? > > With default kernel I haven't seen much noise with most of parsec benchmarks. But the fact that half of parsec benchmark has its own issues with thread-affinity and other things, running parsec with default kernel should be ok. I would think that with the Ubuntu kernels having most of their options as > modules, it shouldn't really be that much of an issue, right? > > For most of us who run CPU intensive workloads it shouldn't be a big issue. For IO intensive or disk intensive workloads, tweaking file system parameters will be help to reduce non-determinism, so it won't randomly perform disk write to flush file-system caches. But if you'r doing heavy IO benchmark, its always good to tweak such kernel parameters. - Avadh > On Fri, Mar 30, 2012 at 10:55 AM, avadh patel <[email protected]> wrote: > >> Does anyone thinks that it will be useful to have a latest Ubuntu disk >> images? >> I have a local 11.10 (natty) disk image that i built recently but it >> doesn't have stripped down kernel image. >> >> Let me know if people are interested in it or not. >> >> - Avadh >> >> On Wed, Mar 28, 2012 at 11:22 AM, Paul Rosenfeld <[email protected]>wrote: >> >>> Ah, good to know, Thanks. >>> >>> On Wed, Mar 28, 2012 at 1:08 PM, Tae Jun Ham <[email protected]> wrote: >>> >>>> Hello, >>>> >>>> >>>> For your information, I tried dist-upgrade, too; however, it also broke >>>> my image (booting part). >>>> >>>> >>>> Thanks >>>> >>>> >>>> -Tae Jun Ham >>>> >>>> >>>> -----Original Message----- >>>> *From:* "Paul Rosenfeld"<[email protected]> >>>> *To:* "marss86-devel"<[email protected]>; >>>> *Cc:* >>>> *Sent:* 2012-03-29 (목) 01:54:48 >>>> *Subject:* [marss86-devel] SSH/RSH/OpenMPI: cautions and suggestions >>>> >>>> Greetings all, >>>> >>>> I have been doing some experimenting and I wanted to share what I've >>>> learned so that in case anyone else finds this thread maybe I can save them >>>> some time. Though it probably won't be that useful to that many people. >>>> >>>> What I've been doing is trying to get some MPI workloads running in >>>> marss using the OpenMPI shared memory interfaces. Now, I know this sort of >>>> defeats the spirit of MPI, but we have an interest in such workloads and >>>> since I can't imagine setting up multiple marss instances with a network >>>> between them to do *actual* message passing is very easy this is one avenue >>>> to run multiple MPI ranks without multiple marss instances. >>>> >>>> I started with the parsec ROI image, converted it to a raw image and >>>> chrooted the image so I could use apt-get and build stuff without the >>>> slowdown of using qemu. >>>> >>>> 0. My initial attempt at simply apt-getting libopenmpi failed and I >>>> thought it was due to an old binary so I built 1.4.5 from source. Though it >>>> turns out the orte_init() error was because of missing ssh/rsh [see #3 >>>> below], so it could be that you can simply apt-get install libopenmpi -- >>>> though I did find some bug reports that the shared memory mode is broken in >>>> 1.3.x, so use at your own peril. >>>> 1. Due to the age of the ubuntu distro, you have to change the entries >>>> in /etc/apt/sources.list to point to old-releases.ubuntu.com and then >>>> run an apt-get update. >>>> 2. Do not try to apt-get openssh-client, this will break your image. >>>> It turns out openssh-client pulls in a few things like mountall and >>>> upstart which confuse the boot process and your root partition won't mount. >>>> I didn't investigate further about why this fails. Perhaps doing a full on >>>> dist-upgrade to pull in new kernels and new libc would have fixed this, but >>>> I didn't try it. >>>> 3. OpenMPI requires either ssh or rsh for some reason even if you're >>>> using the shared memory system and have no networked nodes. Since >>>> installing ssh from apt-get breaks the boot process, you should install >>>> rsh-client -- it pulls in no dependencies and it gets rid of the errors in >>>> orte_init() when trying to run mpirun >>>> 4. To enable the sm mode in MPI, issue the following command: mpirun >>>> -mca btl self,sm -np 4 ./your_mpi_binary >>>> >>>> That's about it. >>>> Happy simulating. >>>> _______________________________________________ >>>> http://www.marss86.org >>>> Marss86-Devel mailing list >>>> [email protected] >>>> https://www.cs.binghamton.edu/mailman/listinfo/marss86-devel >>>> >>> >>> >>> _______________________________________________ >>> http://www.marss86.org >>> Marss86-Devel mailing list >>> [email protected] >>> https://www.cs.binghamton.edu/mailman/listinfo/marss86-devel >>> >>> >> >
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