From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1032535AbeE0BGq (ORCPT ); Sat, 26 May 2018 21:06:46 -0400 Received: from mga17.intel.com ([192.55.52.151]:12722 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751103AbeE0BGp (ORCPT ); Sat, 26 May 2018 21:06:45 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,446,1520924400"; d="scan'208";a="59350730" Subject: [PATCH 0/2] x86/numa_emulation: Introduce uniform split capability From: Dan Williams To: mingo@kernel.org Cc: Wei Yang , "H. Peter Anvin" , x86@kernel.org, Thomas Gleixner , David Rientjes , Ingo Molnar , linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org Date: Sat, 26 May 2018 17:56:47 -0700 Message-ID: <152738260746.11641.13275998345345705617.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-2-gc94f MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The current numa emulation capabilities for splitting System RAM by a fixed size or by a set number of nodes may result in some nodes being larger than others. The implementation prioritizes establishing a minimum usable memory size over satisfying the requested number of numa nodes. Introduce a uniform split capability that evenly partitions each physical numa node into N emulated nodes. For example numa=fake=3U creates 6 emulated nodes total on a system that has 2 physical nodes. This capability is useful for debugging and evaluating platform memory-side-cache capabilities as described by the ACPI HMAT (see 5.2.27.5 Memory Side Cache Information Structure in ACPI 6.2a) See more details in patch2. --- Dan Williams (2): x86/numa_emulation: Fix emulated-to-physical node mapping x86/numa_emulation: Introduce uniform split capability Documentation/x86/x86_64/boot-options.txt | 4 + arch/x86/mm/numa_emulation.c | 98 +++++++++++++++++++++++------ 2 files changed, 82 insertions(+), 20 deletions(-)