Why am I not using 100% of cpu 4491

If they were I-O bound I'd expect to see some time spent in I-O wait.

See:

for a few seconds of trace output. BTW, strace gives a stream of errors like:

umovestr: Input-output error umovestr: Input-output error

I know the processes are doing modest I-O to a disk NFS mounted over infiniband. It was previously mounted over 100 base-T, but switching to infiniband made no improvement.

They don't have any real compebreastion:

---- 13:42:34 up 76 days, 2:48, 5 users, load average: 1.36, 1.54, 1.53 102 processes: 99 sleeping, 3 running, 0 zombie, 0 stopped CPU states: cpu user nice system irq softirq iowait idle total 67.3% 0.0% 2.9% 0.0% 1.9% 0.0% 27.7% cpu00 74.2% 0.0% 4.9% 0.0% 3.9% 0.0% 16.8% cpu01 60.3% 0.0% 0.9% 0.0% 0.0% 0.0% 38.6% Mem: 2024588k av, 2002580k used, 22008k free, 0k shrd, 133944k buff 925472k actv, 548236k ind, 47264k inc Swap: 4194296k av, 0k used, 4194296k free 1398080k cached

PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME CPU COMMAND 20453 bill 25 0 49816 48M 3856 R 37.1 2.4 955:25 0 xyz 20462 bill 25 0 50080 48M 3876 R 33.1 2.4 831:03 1 xyz 21063 root 20 0 1256 1256 956 R 0.0 0.0 0:00 0 top ----

I don't know that I can do anything to give these processes more cycles. At this point I'd be happy just to know why they're not using more.

-- Dave Sill Oak Ridge National Lab, Workstation Support