On Mon, May 08, 2006 at 02:52:07AM -0400, Kris Kennaway wrote: > OK, David's patch fixes the umtx thundering herd (and seems to give a > 4-6% boost). I also fixed a thundering herd in FILEDESC_UNLOCK (which > was also waking up 2-7 CPUs at once about 30% of the time) by doing > s/wakeup/wakeup_one/. This did not seem to give a performance impact > on this test though.
Turning down kern.hz from 1000 to 100 also made a big difference on 12 CPUs (+6.1%). Note also that the system is no less than 40% idle during the runs (at any load), so the bottlenecks are serious. Kris
pgpD5Lh2cjowi.pgp
Description: PGP signature
