From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1B27C43381 for ; Thu, 28 Feb 2019 15:43:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B7A97218AE for ; Thu, 28 Feb 2019 15:43:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551368624; bh=J9WrE2VsWzgE6S/GNSlX6y+qTwLDOpn23JemMH9aEuA=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=yexI+slavTyW1yvVg1KNZXOXJwgnoqhRuoJggAqdOsQfm6KwRyAQYkAk91yyPNCz5 NN1YMqqgXVUlh1iWzefwP0dlmWHjfdMihVDuA7DpssI4AY3er7dt6PatLEE4HiGmGA GGc+t0+d9DYOKBDKLqtVrTPM97/qoqDsXG9Z3lyA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732904AbfB1Pnn (ORCPT ); Thu, 28 Feb 2019 10:43:43 -0500 Received: from mail-ed1-f66.google.com ([209.85.208.66]:46359 "EHLO mail-ed1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726918AbfB1Pnn (ORCPT ); Thu, 28 Feb 2019 10:43:43 -0500 Received: by mail-ed1-f66.google.com with SMTP id f2so17339322edy.13; Thu, 28 Feb 2019 07:43:41 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=KnnpQR0gxcxZFG4JmKjKJF97aHrwdFBLqkL5gz1v6b4=; b=rPd1O6b0IbhqPLxSXfB895v1/t6TD7UOqDbdj6GYpLVQOmwj3Rt5mpeJwUPq6R6ttl bXFRcwQasYN0+xJkllA4yAyQYFcSabfdCtGbvndhGdicTG4Lqtitf9pj6mN0LRwO5PyY je6Ey7mmewHztICxFzNqhxsghszYXPUZ8UYdA0dFEUvhBTTz8AokIORkGTCb8vocY+R2 +EOXjKFu/xM/YA7AB1EvIDordXG/R3ecItpQKN4kGLGPkNGvFbY8wct2XV35koo3x8ZZ TM8OSQd3rPIwgljFG+Q2TL3qKd6tVE8J5HgTOp+nCW1z125Ej1e/tr/Gw+FV3ovEqTcx oH4w== X-Gm-Message-State: AHQUAuaj9Cnn/aY/vAkNovxQg0XGbcdx5zkMGE3LWSYVjbbAOX0eIAJ4 okC+WOTVDtCURDPsOjUCK5sVVxSNZdSuPRPPsk8= X-Google-Smtp-Source: AHgI3IbgWlP8DIKYGnzDmO7EPBRxW4H6GLIc/GpqOVJ+j1FoXTQgzw6tjv9PC/OmJWR5bGcf13BhPlhLBNGpcJtq5RE= X-Received: by 2002:a17:906:d0cb:: with SMTP id bq11mr5828761ejb.185.1551368621113; Thu, 28 Feb 2019 07:43:41 -0800 (PST) MIME-Version: 1.0 References: <204e9bf2afff8e6cb7a8a39d86038075f1bb4ab8.1551160674.git.len.brown@intel.com> In-Reply-To: From: Len Brown Date: Thu, 28 Feb 2019 10:43:29 -0500 Message-ID: Subject: Re: [PATCH 04/14] x86 topology: Add CPUID.1F multi-die/package support To: Dave Hansen Cc: X86 ML , linux-kernel@vger.kernel.org, Len Brown , linux-doc@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 26, 2019 at 2:46 PM Dave Hansen wrote: > > On 2/25/19 10:20 PM, Len Brown wrote: > > -/* leaf 0xb sub-leaf types */ > > +/* extended topology sub-leaf types */ > > #define INVALID_TYPE 0 > > #define SMT_TYPE 1 > > #define CORE_TYPE 2 > > +#define DIE_TYPE 5 > > Looking in the SDM, Vol. 3A "8.9.1 Hierarchical Mapping of Shared > Resources", there are a _couple_ of new levels: Die, Tile and Module. > But, this patch only covers Dies. > > Was there a reason for that? We have software visible modules and tiles in past products, and those were discovered by family/model checks, rather than enumerated. I'm content to let that sleeping dog lay. We don't have software visible modules or die enumerated with this mechanism in any current or about to be current products. When (and if) such products do come along, only then will we know why software *cares* about die and tiles -- and that will be the time to add that support. Per below, I think this series cleanly prepares us for that time. > I wonder if we'll end up with different (better) infrastructure if we do > these all at once instead of hacking them in one at a time. Assuming that "hacking in" is a derogatory term, let me make the case that this patch series cleanly sets the stage for the future. old: thread_siblings: the threads that are in the same core core_siblings: the threads that are in the same package This naming scheme assumed that there would never be a topology level between a core and a package. Though we leave "core_siblings" intact for legacy SW that depends on it, we mark it depreciated. new: core_threads: the threads in the same core die_threads: the threads in the same die package_threads: the threads in the same package So in the future we could always add... dave_threads: the threads in the same dave So I think we are ready for whatever the future may throw at us, while remaining compatible, consistent, and no "hacking in" required. thanks, Len Brown, Intel Open Source Technology Center