From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755530AbYCaM0T (ORCPT ); Mon, 31 Mar 2008 08:26:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753730AbYCaM0K (ORCPT ); Mon, 31 Mar 2008 08:26:10 -0400 Received: from 82-69-137-158.dsl.in-addr.zen.co.uk ([82.69.137.158]:44329 "EHLO uklogin.uk.level5networks.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753582AbYCaM0J (ORCPT ); Mon, 31 Mar 2008 08:26:09 -0400 X-Greylist: delayed 2512 seconds by postgrey-1.27 at vger.kernel.org; Mon, 31 Mar 2008 08:26:08 EDT Date: Mon, 31 Mar 2008 12:44:13 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org Subject: [PATCH][RFC] Add default CPU topology information Message-ID: <20080331114412.GH21637@solarflare.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Not all architectures and configurations define CPU topology information. This can result in an empty topology directory in sysfs, and requires in-kernel users to protect all uses with #ifdef - see . The documentation of CPU topology specifies what the defaults should be if only partial information is available from the hardware. So we can provide these defaults as a fallback. This patch: - Adds default definitions of the 4 topology macros to include/asm-generic/topology.h. - Changes include/asm-*/topology.h to include unconditionally. - Changes drivers/base/topology.c to use the topology macros unconditionally and to cope with definitions that aren't lvalues. - Updates documentation accordingly. Signed-off-by: Ben Hutchings diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt index b61cb95..c035481 100644 --- a/Documentation/cputopology.txt +++ b/Documentation/cputopology.txt @@ -14,9 +14,8 @@ represent the thread siblings to cpu X in the same physical package; To implement it in an architecture-neutral way, a new source file, drivers/base/topology.c, is to export the 4 attributes. -If one architecture wants to support this feature, it just needs to -implement 4 defines, typically in file include/asm-XXX/topology.h. -The 4 defines are: +If one architecture wants to support this feature, it must define +some of these macros in include/asm-XXX/topology.h: #define topology_physical_package_id(cpu) #define topology_core_id(cpu) #define topology_thread_siblings(cpu) @@ -25,17 +24,10 @@ The 4 defines are: The type of **_id is int. The type of siblings is cpumask_t. -To be consistent on all architectures, the 4 attributes should have -default values if their values are unavailable. Below is the rule. -1) physical_package_id: If cpu has no physical package id, -1 is the -default value. -2) core_id: If cpu doesn't support multi-core, its core id is 0. -3) thread_siblings: Just include itself, if the cpu doesn't support -HT/multi-thread. -4) core_siblings: Just include itself, if the cpu doesn't support -multi-core and HT/Multi-thread. - -So be careful when declaring the 4 defines in include/asm-XXX/topology.h. - -If an attribute isn't defined on an architecture, it won't be exported. - +To be consistent on all architectures, include/asm-generic/topology.h +provides default definitions for any of the above macros that are +not already defined: +1) physical_package_id: -1 +2) core_id: 0 +3) thread_siblings: just the given CPU +4) core_siblings: just the given CPU diff --git a/drivers/base/topology.c b/drivers/base/topology.c index e1d3ad4..dfcb2e2 100644 --- a/drivers/base/topology.c +++ b/drivers/base/topology.c @@ -45,47 +45,28 @@ static ssize_t show_##name(struct sys_device *dev, char *buf) \ { \ ssize_t len = -1; \ unsigned int cpu = dev->id; \ - len = cpumask_scnprintf(buf, NR_CPUS+1, topology_##name(cpu)); \ + cpumask_t siblings = topology_##name(cpu); \ + len = cpumask_scnprintf(buf, NR_CPUS+1, siblings); \ return (len + sprintf(buf + len, "\n")); \ } -#ifdef topology_physical_package_id define_id_show_func(physical_package_id); define_one_ro(physical_package_id); -#define ref_physical_package_id_attr &attr_physical_package_id.attr, -#else -#define ref_physical_package_id_attr -#endif -#ifdef topology_core_id define_id_show_func(core_id); define_one_ro(core_id); -#define ref_core_id_attr &attr_core_id.attr, -#else -#define ref_core_id_attr -#endif -#ifdef topology_thread_siblings define_siblings_show_func(thread_siblings); define_one_ro(thread_siblings); -#define ref_thread_siblings_attr &attr_thread_siblings.attr, -#else -#define ref_thread_siblings_attr -#endif -#ifdef topology_core_siblings define_siblings_show_func(core_siblings); define_one_ro(core_siblings); -#define ref_core_siblings_attr &attr_core_siblings.attr, -#else -#define ref_core_siblings_attr -#endif static struct attribute *default_attrs[] = { - ref_physical_package_id_attr - ref_core_id_attr - ref_thread_siblings_attr - ref_core_siblings_attr + &attr_physical_package_id.attr, + &attr_core_id.attr, + &attr_thread_siblings.attr, + &attr_core_siblings.attr, NULL }; diff --git a/include/asm-alpha/topology.h b/include/asm-alpha/topology.h index 420ccde..e59ec8a 100644 --- a/include/asm-alpha/topology.h +++ b/include/asm-alpha/topology.h @@ -41,8 +41,8 @@ static inline cpumask_t node_to_cpumask(int node) #define pcibus_to_cpumask(bus) (cpu_online_map) -#else /* CONFIG_NUMA */ -# include -#endif /* !CONFIG_NUMA */ +#endif /* CONFIG_NUMA */ + +#include #endif /* _ASM_ALPHA_TOPOLOGY_H */ diff --git a/include/asm-frv/topology.h b/include/asm-frv/topology.h index abe7298..9427243 100644 --- a/include/asm-frv/topology.h +++ b/include/asm-frv/topology.h @@ -5,10 +5,8 @@ #error NUMA not supported yet -#else /* !CONFIG_NUMA */ +#endif /* CONFIG_NUMA */ #include -#endif /* CONFIG_NUMA */ - #endif /* _ASM_TOPOLOGY_H */ diff --git a/include/asm-generic/topology.h b/include/asm-generic/topology.h index 342a2a0..373502b 100644 --- a/include/asm-generic/topology.h +++ b/include/asm-generic/topology.h @@ -27,6 +27,8 @@ #ifndef _ASM_GENERIC_TOPOLOGY_H #define _ASM_GENERIC_TOPOLOGY_H +#include + /* Other architectures wishing to use this simple topology API should fill in the below functions as appropriate in their own file. */ #ifndef cpu_to_node @@ -52,4 +54,17 @@ ) #endif +#ifndef topology_physical_package_id +#define topology_physical_package_id(cpu) ((void)(cpu), -1) +#endif +#ifndef topology_core_id +#define topology_core_id(cpu) ((void)(cpu), 0) +#endif +#ifndef topology_thread_siblings +#define topology_thread_siblings(cpu) cpumask_of_cpu(cpu) +#endif +#ifndef topology_core_siblings +#define topology_core_siblings(cpu) cpumask_of_cpu(cpu) +#endif + #endif /* _ASM_GENERIC_TOPOLOGY_H */ diff --git a/include/asm-mips/topology.h b/include/asm-mips/topology.h index 259145e..ce837a4 100644 --- a/include/asm-mips/topology.h +++ b/include/asm-mips/topology.h @@ -8,10 +8,10 @@ #ifndef __ASM_TOPOLOGY_H #define __ASM_TOPOLOGY_H -#include - #ifdef CONFIG_SMP #define smt_capable() (smp_num_siblings > 1) #endif +#include + #endif /* __ASM_TOPOLOGY_H */ diff --git a/include/asm-powerpc/topology.h b/include/asm-powerpc/topology.h index ca23b68..e587788 100644 --- a/include/asm-powerpc/topology.h +++ b/include/asm-powerpc/topology.h @@ -96,9 +96,6 @@ static inline void sysfs_remove_device_from_node(struct sys_device *dev, { } - -#include - #endif /* CONFIG_NUMA */ #ifdef CONFIG_SMP @@ -112,5 +109,7 @@ static inline void sysfs_remove_device_from_node(struct sys_device *dev, #endif #endif +#include + #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_TOPOLOGY_H */ diff --git a/include/asm-x86/topology.h b/include/asm-x86/topology.h index 8af05a9..7f31b8d 100644 --- a/include/asm-x86/topology.h +++ b/include/asm-x86/topology.h @@ -165,11 +165,7 @@ extern int __node_distance(int, int); #define node_distance(a, b) __node_distance(a, b) #endif -#else /* CONFIG_NUMA */ - -#include - -#endif +#endif /* CONFIG_NUMA */ extern cpumask_t cpu_coregroup_map(int cpu); @@ -185,4 +181,6 @@ extern cpumask_t cpu_coregroup_map(int cpu); #define smt_capable() (smp_num_siblings > 1) #endif +#include + #endif -- Ben Hutchings, Senior Software Engineer, Solarflare Communications Not speaking for my employer; that's the marketing department's job.