Hi, [Sorry for the delay, I got a bit sidetrack'ed...]
2012/2/17 Alexander Motin <m...@freebsd.org>: > On 17.02.2012 18:53, Arnaud Lacombe wrote: >> >> On Fri, Feb 17, 2012 at 11:29 AM, Alexander Motin<m...@freebsd.org> wrote: >>> >>> On 02/15/12 21:54, Jeff Roberson wrote: >>>> >>>> On Wed, 15 Feb 2012, Alexander Motin wrote: >>>>> >>>>> I've decided to stop those cache black magic practices and focus on >>>>> things that really exist in this world -- SMT and CPU load. I've >>>>> dropped most of cache related things from the patch and made the rest >>>>> of things more strict and predictable: >>>>> http://people.freebsd.org/~mav/sched.htt34.patch >>>> >>>> >>>> This looks great. I think there is value in considering the other >>>> approach further but I would like to do this part first. It would be >>>> nice to also add priority as a greater influence in the load balancing >>>> as well. >>> >>> >>> I haven't got good idea yet about balancing priorities, but I've >>> rewritten >>> balancer itself. As soon as sched_lowest() / sched_highest() are more >>> intelligent now, they allowed to remove topology traversing from the >>> balancer itself. That should fix double-swapping problem, allow to keep >>> some >>> affinity while moving threads and make balancing more fair. I did number >>> of >>> tests running 4, 8, 9 and 16 CPU-bound threads on 8 CPUs. With 4, 8 and >>> 16 >>> threads everything is stationary as it should. With 9 threads I see >>> regular >>> and random load move between all 8 CPUs. Measurements on 5 minutes run >>> show >>> deviation of only about 5 seconds. It is the same deviation as I see >>> caused >>> by only scheduling of 16 threads on 8 cores without any balancing needed >>> at >>> all. So I believe this code works as it should. >>> >>> Here is the patch: http://people.freebsd.org/~mav/sched.htt40.patch >>> >>> I plan this to be a final patch of this series (more to come :)) and if >>> there will be no problems or objections, I am going to commit it (except >>> some debugging KTRs) in about ten days. So now it's a good time for >>> reviews >>> and testing. :) >>> >> is there a place where all the patches are available ? > > > All my scheduler patches are cumulative, so all you need is only the last > mentioned here sched.htt40.patch. > You may want to have a look to the result I collected in the `runs/freebsd-experiments' branch of: https://github.com/lacombar/hackbench/ and compare them with vanilla FreeBSD 9.0 and -CURRENT results available in `runs/freebsd'. On the dual package platform, your patch is not a definite win. > But in some cases, especially for multi-socket systems, to let it show its > best, you may want to apply additional patch from avg@ to better detect CPU > topology: > https://gitorious.org/~avg/freebsd/avgbsd/commit/6bca4a2e4854ea3fc275946a023db65c483cb9dd > test I conducted specifically for this patch did not showed much improvement... - Arnaud _______________________________________________ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
