From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 9AF2A6B000D for ; Fri, 6 Jul 2018 12:18:25 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id l21-v6so3036579pff.3 for ; Fri, 06 Jul 2018 09:18:25 -0700 (PDT) Received: from mga03.intel.com (mga03.intel.com. [134.134.136.65]) by mx.google.com with ESMTPS id e1-v6si8988867pfg.257.2018.07.06.09.18.24 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 06 Jul 2018 09:18:24 -0700 (PDT) Subject: [PATCH v2 0/2] x86/numa_emulation: Introduce uniform split capability From: Dan Williams Date: Fri, 06 Jul 2018 09:07:55 -0700 Message-ID: <153089327581.27680.11402583130804677094.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: 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.orgx86@kernel.org Changes since v1 [1]: * Fix a pair of compile errors in 32-bit builds for 64-bit divides. [1]: https://lkml.org/lkml/2018/5/26/190 --- 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 | 107 ++++++++++++++++++++++++----- 2 files changed, 91 insertions(+), 20 deletions(-)