On Mon, May 08, 2006 at 06:18:18PM -0700, Maxim Sobolev wrote: > Kris Kennaway wrote: > >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. > > Maybe HDD just can't keep up with the pace?
There is no disk I/O involved. Kris
pgpIlBnst4hxb.pgp
Description: PGP signature
