Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757027Ab1FPMLy (ORCPT ); Thu, 16 Jun 2011 08:11:54 -0400 Received: from mail2-relais-roc.national.inria.fr ([192.134.164.83]:40768 "EHLO mail2-relais-roc.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756224Ab1FPMLt (ORCPT ); Thu, 16 Jun 2011 08:11:49 -0400 X-IronPort-AV: E=Sophos;i="4.65,375,1304287200"; d="scan'208";a="96872922" Date: Thu, 16 Jun 2011 14:11:47 +0200 From: Samuel Thibault To: mingo@elte.hu, peterz@infradead.org Cc: linux-kernel@vger.kernel.org Subject: "Cache" sched domains Message-ID: <20110616121147.GA4644@const.bordeaux.inria.fr> Mail-Followup-To: Samuel Thibault , mingo@elte.hu, peterz@infradead.org, linux-kernel@vger.kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit User-Agent: Mutt/1.5.12-2006-07-14 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3624 Lines: 35 Hello, We have an x86 machine whose sockets look like this in hwloc: ┌──────────────────────────────────────────────────────────────────┐ │Socket P#1 │ │┌────────────────────────────────────────────────────────────────┐│ ││L3 (16MB) ││ │└────────────────────────────────────────────────────────────────┘│ │┌────────────────────┐┌────────────────────┐┌────────────────────┐│ ││L2 (3072KB) ││L2 (3072KB) ││L2 (3072KB) ││ │└────────────────────┘└────────────────────┘└────────────────────┘│ │┌─────────┐┌─────────┐┌─────────┐┌─────────┐┌─────────┐┌─────────┐│ ││L1 (32KB)││L1 (32KB)││L1 (32KB)││L1 (32KB)││L1 (32KB)││L1 (32KB)││ │└─────────┘└─────────┘└─────────┘└─────────┘└─────────┘└─────────┘│ │┌─────────┐┌─────────┐┌─────────┐┌─────────┐┌─────────┐┌─────────┐│ ││Core P#0 ││Core P#1 ││Core P#2 ││Core P#3 ││Core P#4 ││Core P#5 ││ ││┌───────┐││┌───────┐││┌───────┐││┌───────┐││┌───────┐││┌───────┐││ │││PU P#0 ││││PU P#4 ││││PU P#8 ││││PU P#12││││PU P#16││││PU P#20│││ ││└───────┘││└───────┘││└───────┘││└───────┘││└───────┘││└───────┘││ │└─────────┘└─────────┘└─────────┘└─────────┘└─────────┘└─────────┘│ └──────────────────────────────────────────────────────────────────┘ However, Linux does not build sched domains for the pairs of cores which share an L2 cache. On s390, IBM added sched domains for books, that is, sets of cores which share an L2 cache. The support should probably be added in a generic way for all archs thanks to generic cache information. Samuel -- 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/