From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752800AbbEDK3x (ORCPT ); Mon, 4 May 2015 06:29:53 -0400 Received: from mail-wi0-f173.google.com ([209.85.212.173]:34673 "EHLO mail-wi0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752181AbbEDK2e (ORCPT ); Mon, 4 May 2015 06:28:34 -0400 From: Bartosz Golaszewski To: LKML Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, "Rafael J. Wysocki" , Viresh Kumar , Guenter Roeck , Jean Delvare , Fenghua Yu , Benoit Cousson , Jonathan Corbet , Oleg Drokin , Russell King , Catalin Marinas , Bartosz Golaszewski Subject: [PATCH v2 2/9] Documentation: update cputopology.txt Date: Mon, 4 May 2015 12:28:17 +0200 Message-Id: <1430735304-14866-3-git-send-email-bgolaszewski@baylibre.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1430735304-14866-1-git-send-email-bgolaszewski@baylibre.com> References: <1430735304-14866-1-git-send-email-bgolaszewski@baylibre.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The documentation on cpu topology seems to be a bit out-of-date. It doesn't mention the **_siblings_list attributes and uses old names for topology_**_cpumask() macros. Add information on missing attributes plus some additional clarifications. Signed-off-by: Bartosz Golaszewski --- Documentation/cputopology.txt | 35 ++++++++++++++++++++++++++--------- 1 file changed, 26 insertions(+), 9 deletions(-) diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt index 428a961..12b1b25 100644 --- a/Documentation/cputopology.txt +++ b/Documentation/cputopology.txt @@ -1,6 +1,6 @@ Export CPU topology info via sysfs. Items (attributes) are similar -to /proc/cpuinfo. +to /proc/cpuinfo output of some architectures: 1) /sys/devices/system/cpu/cpuX/topology/physical_package_id: @@ -23,20 +23,35 @@ to /proc/cpuinfo. 4) /sys/devices/system/cpu/cpuX/topology/thread_siblings: internal kernel map of cpuX's hardware threads within the same - core as cpuX + core as cpuX. -5) /sys/devices/system/cpu/cpuX/topology/core_siblings: +5) /sys/devices/system/cpu/cpuX/topology/thread_siblings_list: + + human-readable list of cpuX's hardware threads within the same + core as cpuX. + +6) /sys/devices/system/cpu/cpuX/topology/core_siblings: internal kernel map of cpuX's hardware threads within the same physical_package_id. -6) /sys/devices/system/cpu/cpuX/topology/book_siblings: +7) /sys/devices/system/cpu/cpuX/topology/core_siblings_list: + + human-readable list of cpuX's hardware threads within the same + physical_package_id. + +8) /sys/devices/system/cpu/cpuX/topology/book_siblings: internal kernel map of cpuX's hardware threads within the same book_id. +9) /sys/devices/system/cpu/cpuX/topology/book_siblings_list: + + human-readable list of cpuX's hardware threads within the same + book_id. + To implement it in an architecture-neutral way, a new source file, -drivers/base/topology.c, is to export the 4 or 6 attributes. The two book +drivers/base/topology.c, is to export the 6 or 9 attributes. The three book related sysfs files will only be created if CONFIG_SCHED_BOOK is selected. For an architecture to support this feature, it must define some of @@ -48,16 +63,18 @@ these macros in include/asm-XXX/topology.h: #define topology_core_cpumask(cpu) #define topology_book_cpumask(cpu) -The type of **_id is int. -The type of siblings is (const) struct cpumask *. +The type of **_id macros is int. +The type of **_cpumask macros is (const) struct cpumask *. The latter +correspond with appropriate **_siblings sysfs attributes (except for +topology_sibling_cpumask() which corresponds with thread_siblings). To be consistent on all architectures, include/linux/topology.h provides default definitions for any of the above macros that are not defined by include/asm-XXX/topology.h: 1) physical_package_id: -1 2) core_id: 0 -3) thread_siblings: just the given CPU -4) core_siblings: just the given CPU +3) sibling_cpumask: just the given CPU +4) core_cpumask: just the given CPU For architectures that don't support books (CONFIG_SCHED_BOOK) there are no default definitions for topology_book_id() and topology_book_cpumask(). -- 2.1.4