From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-x22f.google.com (mail-pf0-x22f.google.com [IPv6:2607:f8b0:400e:c00::22f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3vYpQ16WjLzDq66 for ; Thu, 2 Mar 2017 21:26:33 +1100 (AEDT) Received: by mail-pf0-x22f.google.com with SMTP id w189so20907017pfb.0 for ; Thu, 02 Mar 2017 02:26:33 -0800 (PST) Subject: Re: [PATCH 5/5] powerpc/smp: Add Power9 scheduler topology To: Oliver O'Halloran , linuxppc-dev@lists.ozlabs.org References: <20170302004920.21948-1-oohall@gmail.com> <20170302004920.21948-5-oohall@gmail.com> From: Balbir Singh Message-ID: <3ef222c7-15f7-e981-394d-61cf4b26a1cc@gmail.com> Date: Thu, 2 Mar 2017 21:25:59 +1100 MIME-Version: 1.0 In-Reply-To: <20170302004920.21948-5-oohall@gmail.com> Content-Type: text/plain; charset=windows-1252 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 02/03/17 11:49, Oliver O'Halloran wrote: > In previous generations of Power processors each core had a private L2 > cache. The Power9 processor has a slightly different architecture where > the L2 cache is shared among pairs of cores rather than being completely > private. > > Making the scheduler aware of this cache sharing allows the scheduler to > make more intelligent migration decisions. When one core in the pair is > overloaded tasks can be migrated to its paired core to improve throughput > without cache-refilling penality typically associated with task > migration. Could you please describe the changes to sched_domains w.r.t before and after for P9. I think most of the changes make sense, but some data to back them up including any results you have to show that these patches help would be nice Balbir Singh.