Date: Fri, 17 Feb 2012 11:53:14 -0500 From: Arnaud Lacombe <lacombar@gmail.com> To: Alexander Motin <mav@freebsd.org> Cc: freebsd-hackers@freebsd.org, Florian Smeets <flo@freebsd.org>, Jeff Roberson <jroberson@jroberson.net>, Andriy Gapon <avg@freebsd.org>, FreeBSD current <freebsd-current@freebsd.org> Subject: Re: [RFT][patch] Scheduling for HTT and not only Message-ID: <CACqU3MWEC4YYguPQF_d%2B_i_CwTc=86hG%2BPbxFgJQiUS-=AHiRw@mail.gmail.com> In-Reply-To: <4F3E807A.60103@FreeBSD.org> References: <4F2F7B7F.40508@FreeBSD.org> <4F366E8F.9060207@FreeBSD.org> <4F367965.6000602@FreeBSD.org> <4F396B24.5090602@FreeBSD.org> <alpine.BSF.2.00.1202131012270.2020@desktop> <4F3978BC.6090608@FreeBSD.org> <alpine.BSF.2.00.1202131108460.2020@desktop> <4F3990EA.1080002@FreeBSD.org> <4F3C0BB9.6050101@FreeBSD.org> <alpine.BSF.2.00.1202150949480.2020@desktop> <4F3E807A.60103@FreeBSD.org>
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Hi, On Fri, Feb 17, 2012 at 11:29 AM, Alexander Motin <mav@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 ? I intend to run some tests on a 1x2x2 (atom D510), 1x4x1 (core-2 quad), and eventually a 2x8x2 platforms, against r231573. Results should hopefully be available by the end of the week-end/middle of next week[0]. - Arnaud [0]: the D510 will likely be testing a couple of Linux kernel over the week-end, and a FreeBSD run takes about 2.5 days to complete. > > -- > Alexander Motin > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org"
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