From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757891Ab3BRFxH (ORCPT ); Mon, 18 Feb 2013 00:53:07 -0500 Received: from e28smtp02.in.ibm.com ([122.248.162.2]:55252 "EHLO e28smtp02.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750764Ab3BRFxF (ORCPT ); Mon, 18 Feb 2013 00:53:05 -0500 Message-ID: <5121C1B3.3090100@linux.vnet.ibm.com> Date: Mon, 18 Feb 2013 13:52:51 +0800 From: Michael Wang User-Agent: Mozilla/5.0 (X11; Linux i686; rv:16.0) Gecko/20121011 Thunderbird/16.0.1 MIME-Version: 1.0 To: LKML , Ingo Molnar , Peter Zijlstra CC: Paul Turner , Mike Galbraith , Andrew Morton , alex.shi@intel.com, Ram Pai , "Nikunj A. Dadhania" , Namhyung Kim Subject: Re: [RFC PATCH v3 0/3] sched: simplify the select_task_rq_fair() References: <51079178.3070002@linux.vnet.ibm.com> In-Reply-To: <51079178.3070002@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13021805-5816-0000-0000-000006B84A9D Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/29/2013 05:08 PM, Michael Wang wrote: > v3 change log: > Fix small logical issues (Thanks to Mike Galbraith). > Change the way of handling WAKE. > > This patch set is trying to simplify the select_task_rq_fair() with > schedule balance map. > > After get rid of the complex code and reorganize the logical, pgbench show > the improvement, more the clients, bigger the improvement. > > Prev: Post: > > | db_size | clients | | tps | | tps | > +---------+---------+ +-------+ +-------+ > | 22 MB | 1 | | 10788 | | 10881 | > | 22 MB | 2 | | 21617 | | 21837 | > | 22 MB | 4 | | 41597 | | 42645 | > | 22 MB | 8 | | 54622 | | 57808 | > | 22 MB | 12 | | 50753 | | 54527 | > | 22 MB | 16 | | 50433 | | 56368 | +11.77% > | 22 MB | 24 | | 46725 | | 54319 | +16.25% > | 22 MB | 32 | | 43498 | | 54650 | +25.64% > | 7484 MB | 1 | | 7894 | | 8301 | > | 7484 MB | 2 | | 19477 | | 19622 | > | 7484 MB | 4 | | 36458 | | 38242 | > | 7484 MB | 8 | | 48423 | | 50796 | > | 7484 MB | 12 | | 46042 | | 49938 | > | 7484 MB | 16 | | 46274 | | 50507 | +9.15% > | 7484 MB | 24 | | 42583 | | 49175 | +15.48% > | 7484 MB | 32 | | 36413 | | 49148 | +34.97% > | 15 GB | 1 | | 7742 | | 7876 | > | 15 GB | 2 | | 19339 | | 19531 | > | 15 GB | 4 | | 36072 | | 37389 | > | 15 GB | 8 | | 48549 | | 50570 | > | 15 GB | 12 | | 45716 | | 49542 | > | 15 GB | 16 | | 46127 | | 49647 | +7.63% > | 15 GB | 24 | | 42539 | | 48639 | +14.34% > | 15 GB | 32 | | 36038 | | 48560 | +34.75% > > Please check the patch for more details about schedule balance map. > > Support the NUMA domain but not well tested. > Support the rebuild of domain but not tested. Hi, Ingo, Peter I've finished the test I could figure out (NUMA, domain rebuild...) , no issue appear on my box. I think this patch set will benefit the system, especially when there are huge amount of cpus. How do you think about this idea? do you have any comments on the patch set? Regards, Michael Wang > > Comments are very welcomed. > > Behind the v3: > Some changes has been applied to the way of handling WAKE. > > And that's all around one question, whether we should do load balance > for WAKE or not? > > In the old world, the only chance to do load balance for WAKE is when > prev cpu and curr cpu are not cache affine, but that doesn't make sense. > > I suppose the real meaning behind that logical is, do balance only if > cache benefit nothing after changing cpu. > > However, select_idle_sibling() is not only designed for the purpose to > take care of cache, it also benefit latency, and cost less than the > balance path. > > Besides, it's impossible to estimate the benefit of doing load balance > at that point of time. > > And that's come out the v3, no load balance for WAKE. > > Test with: > 12 cpu X86 server and linux-next 3.8.0-rc3. > > Michael Wang (3): > [RFC PATCH v3 1/3] sched: schedule balance map foundation > [RFC PATCH v3 2/3] sched: build schedule balance map > [RFC PATCH v3 3/3] sched: simplify select_task_rq_fair() with schedule balance map > > Signed-off-by: Michael Wang > --- > b/kernel/sched/core.c | 44 +++++++++++++++ > b/kernel/sched/fair.c | 135 ++++++++++++++++++++++++++----------------------- > b/kernel/sched/sched.h | 14 +++++ > kernel/sched/core.c | 67 ++++++++++++++++++++++++ > 4 files changed, 199 insertions(+), 61 deletions(-) > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >