From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 42Kb5G4zxszF3Fg for ; Wed, 26 Sep 2018 08:16:32 +1000 (AEST) Subject: Re: [PATCH v8 0/3] powerpc: Detection and scheduler optimization for POWER9 bigcore To: ego@linux.vnet.ibm.com References: <1537464159-25919-1-git-send-email-ego@linux.vnet.ibm.com> <133c7bca-5720-81de-7956-b93870a1bab8@intel.com> <20180922110340.GA1402@in.ibm.com> Cc: "Aneesh Kumar K.V" , Srikar Dronamraju , Michael Ellerman , Benjamin Herrenschmidt , Michael Neuling , Vaidyanathan Srinivasan , Akshay Adiga , Shilpasri G Bhat , Oliver O'Halloran , Nicholas Piggin , Murilo Opsfelder Araujo , Anton Blanchard , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org From: Dave Hansen Message-ID: Date: Tue, 25 Sep 2018 15:16:30 -0700 MIME-Version: 1.0 In-Reply-To: <20180922110340.GA1402@in.ibm.com> Content-Type: text/plain; charset=utf-8 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 09/22/2018 04:03 AM, Gautham R Shenoy wrote: > Without this patchset, the SMT domain would be defined as the group of > threads that share L2 cache. Could you try to make a more clear, concise statement about the current state of the art vs. what you want it to be? Right now, the sched domains do something like this in terms of ordering: 1. SMT siblings 2. Caches 3. NUMA It sounds like you don't want SMT siblings to be the things that we use, right? Because some siblings share caches and some do not. Right? You want something like this: 1. SMT siblings (sharing L1) 2. SMT siblings (sharing L2) 3. Other caches 4. NUMA