Am 01.09.2010 um 12:15 schrieb Marian Marinov: > On Wednesday 01 September 2010 11:47:29 Reuti wrote: >> Am 01.09.2010 um 09:34 schrieb Christopher Samuel: >>> -----BEGIN PGP SIGNED MESSAGE----- >>> Hash: SHA1 >>> >>> On 01/09/10 01:58, Reuti wrote: >>>> With recent kernels also (kernel) processes in D state >>>> count as running. >>> >>> I wouldn't say recent, that goes back as far as I can >>> remember. >>> >>> For instance I've seen RHEL3 (2.4.x - sort of) NFS servers >>> with load averages in the 80's where they were run with a lot >>> of nfsd's that were blocked waiting for I/O due to ext3. >> >> My impression was always (as there is a similar setting for the >> load_threshold in OGE), that it should limit the number of jobs on a big >> SMP machine when you oversubscribe by intention, as not all parallel jobs >> are really using all the CPU power over their lifetime (maybe such a >> machine was even operated w/o any NFS). Then allowing e.g. 72 slots for >> jobs on a 60 core maschine might get most out of it with a load near 100%. >> >> Well, getting now 12 cores in newer CPUs and assemble them to 24 or 48 core >> machines would make such a setting useful again. Maybe the load sensor >> should honor only the scheduled jobs' load. >> >> -- Reuti >> >>> cheers! >>> Chris > > I believe that the load threshold should be set depending on the type of jobs > you run on your compute nodes. > > In some cases the load is not linked only to disk/network I/O and CPU, > sometimes the jobs do a lot of in memory changes which bring more weight
I thought the load is just the number of processes which are eligible to run and in addition today which are in D state. But a single serial process w/o threads or forks shouldn't get the load over 1 by writing a lot to memory. -- Reuti > then > the actual CPU or disk/network I/O. So for example a load average of 15 can > also be considered for normal load, as far as the system is still responsive > and the jobs time don't degrade. > > -- > Best regards, > Marian Marinov > _______________________________________________ > Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing > To change your subscription (digest mode or unsubscribe) visit > http://www.beowulf.org/mailman/listinfo/beowulf _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
