On Tue, Apr 07, 2009 at 03:18:31PM -0400, George Bosilca wrote: > Steve, > > I spotted a strange value for the mpi_yield_when_idle MCA parameter. 1 > means your processor is oversubscribed, and this trigger a call to > sched_yield after each check on the SM. Are you running the job > oversubscribed? If not it looks like somehow we don't correctly > identify that there are multiple cores ... > > george. >
The node is not oversubscribed. Here's top(1) output last pid: 90265; load averages: 0.79, 0.40, 0.28 up 89+18:30:27 12:33:36 31 processes: 3 running, 28 sleeping CPU: 2.3% user, 0.0% nice, 25.8% system, 0.4% interrupt, 71.5% idle Mem: 27M Active, 28G Inact, 748M Wired, 1304M Cache, 617M Buf, 840M Free Swap: 4096M Total, 4096M Free PID USERNAME THR PRI NICE SIZE RES STATE C TIME WCPU COMMAND 90264 kargl 1 101 0 170M 12012K CPU1 1 0:32 98.46% z 90265 kargl 1 101 0 170M 4320K CPU2 2 0:32 97.01% z 756 root 1 4 0 4668K 928K - 7 8:36 0.00% nfsd 757 root 1 4 0 4668K 932K - 7 7:57 0.00% nfsd z is the netpipe executable. This node has 2 quad-core opteron processors. I also see the slowdown if I used node19 instead of node20. 19 and 20 are identical blades. -- Steve
