On Wed, May 21, 2008 at 08:11:30PM +0200, Zeljko Vrba wrote: > On Wed, May 21, 2008 at 07:24:50PM +0200, Henrik Johansson wrote: > > > > Total idle time reported by vmstat is about 60-80% and mpstat shows > > that no cpu(hwthread) is utilized to even near the 100%. I've also > > seen that the run queue sometimes goes up to 2 while we still have > > lots of cpu-time left. > > > > The OS-instance have ~3k5 processes running with ~ 31k6 threads. > > > Your experience coincides exactly with my own experiments. A small D > script that was recently posted here in another thread reported most > of the time being used in unix`idle. I haven't bothered to find out > the exact cause.
You mean, the system is idle? What thread are you talking about? > See these two threads: > > http://www.opensolaris.org/jive/thread.jspa?threadID=57013&tstart=15 > http://www.opensolaris.org/jive/thread.jspa?threadID=57030&tstart=15 > > You probably also want to look at syscall and context switch rates and > maybe truss(1) the processes to see which syscalls it uses the most. Please avoid using truss for performance analysis - especially when looking at context switches too: http://www.brendangregg.com/DTrace/dtracevstruss.html For syscalls by process, just use: # dtrace -n 'syscall:::entry { @[execname, probefunc] = count(); }' procsystime from the DTraceToolkit formats it nicely, and can measure elapsed and on-CPU times. Or roll your own - it's an easy script. Brendan -- Brendan [CA, USA] _______________________________________________ perf-discuss mailing list perf-discuss@opensolaris.org
