Thanks, Steve, but the blog does not answer my question. With vmstat reporting 50% idle time, and the core greatly under-utilised (about 25%), how do you determine that a *single thread* has reached its limit? I would expect 0% idle time on vmstat in that case. The main issue is that the number of instructions-per-second that a thread can execute depends on its own CPI, but also on the execution pattern of the other threads in the core. So a thread that can do 700 instructions/sec, if running alone on the core, will do much less when sharing the core with other threads. Thus, you're left with mpstat to tell you whether the thread is saturated. Only I'm not sure whether mpstat is doing the right thing.
--Elad Steve Sistare wrote: > See Ravi Talashikar's blog for an explanation of CPU vs core > utilization on CMT architectures such as the T1000: > http://blogs.sun.com/travi/entry/ultrasparc_t1_utilization_explained > > - Steve _______________________________________________ perf-discuss mailing list perf-discuss@opensolaris.org
