At 01:55 PM 8/29/2011, Bruce Cran wrote:
Actually, the ULE scheduler does know about HyperThreading and the topology of such CPUs. I don't know what it does with the information, but it probably works to optimize cache usage etc.
Alas, during a recent kernel build, I used the -j2 command line option in "make" and watched as the scheduler repeatedly assigned two instances of cc (the most CPU-intensive program) to the same core.
During that process, I also watched CPU utilization in top(1). The peak was 46% idle, which means that HTT appeared to be making at most a 4% difference. (If the peak were 50% idle, HTT would be doing nothing at all, because top(1) can't tell that there aren't really 4 CPUs.)
--Brett Glass _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
