From: Zhang, Yanmin The patch implements cpu topology exportation by sysfs. Items (attributes) are similar to /proc/cpuinfo. 1) /sys/devices/system/cpu/cpuX/topology/physical_package_id: represent the physical package id of cpu X; 2) /sys/devices/system/cpu/cpuX/topology/core_id: represent the cpu core id to cpu X; 3) /sys/devices/system/cpu/cpuX/topology/thread_siblings: represent the thread siblings to cpu X in the same core; 4) /sys/devices/system/cpu/cpuX/topology/core_siblings: represent the thread siblings to cpu X in the same physical package; To implement it in an architecture-neutral way, a new source file, driver/base/topology.c, is to export the 5 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: #define topology_physical_package_id(cpu) #define topology_core_id(cpu) #define topology_thread_siblings(cpu) #define topology_core_siblings(cpu) The type of **_id is int. The type of siblings is cpumask_t. To be consistent on all architectures, the 4 attributes should have deafult 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. Thank Nathan, Greg, Andi, Paul and Venki. The patch provides defines for i386/x86_64/ia64. Signed-off-by: Zhang, Yanmin Cc: Ingo Molnar Cc: Nick Piggin Cc: Greg KH Signed-off-by: Andrew Morton --- Documentation/cputopology.txt | 41 ++++++++ arch/ia64/kernel/topology.c | 2 drivers/base/Makefile | 1 drivers/base/topology.c | 148 ++++++++++++++++++++++++++++++++ include/asm-i386/topology.h | 9 + include/asm-ia64/topology.h | 7 + include/asm-x86_64/topology.h | 9 + 7 files changed, 216 insertions(+), 1 deletion(-) diff -puN arch/ia64/kernel/topology.c~export-cpu-topology-by-sysfs arch/ia64/kernel/topology.c --- devel/arch/ia64/kernel/topology.c~export-cpu-topology-by-sysfs 2006-01-25 10:57:27.000000000 -0800 +++ devel-akpm/arch/ia64/kernel/topology.c 2006-01-25 10:57:27.000000000 -0800 @@ -98,4 +98,4 @@ out: return err; } -__initcall(topology_init); +subsys_initcall(topology_init); diff -puN /dev/null Documentation/cputopology.txt --- /dev/null 2003-09-15 06:40:47.000000000 -0700 +++ devel-akpm/Documentation/cputopology.txt 2006-01-25 10:57:27.000000000 -0800 @@ -0,0 +1,41 @@ + +Export cpu topology info by sysfs. Items (attributes) are similar +to /proc/cpuinfo. + +1) /sys/devices/system/cpu/cpuX/topology/physical_package_id: +represent the physical package id of cpu X; +2) /sys/devices/system/cpu/cpuX/topology/core_id: +represent the cpu core id to cpu X; +3) /sys/devices/system/cpu/cpuX/topology/thread_siblings: +represent the thread siblings to cpu X in the same core; +4) /sys/devices/system/cpu/cpuX/topology/core_siblings: +represent the thread siblings to cpu X in the same physical package; + +To implement it in an architecture-neutral way, a new source file, +driver/base/topology.c, is to export the 5 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: +#define topology_physical_package_id(cpu) +#define topology_core_id(cpu) +#define topology_thread_siblings(cpu) +#define topology_core_siblings(cpu) + +The type of **_id is int. +The type of siblings is cpumask_t. + +To be consistent on all architectures, the 4 attributes should have +deafult 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. + diff -puN drivers/base/Makefile~export-cpu-topology-by-sysfs drivers/base/Makefile --- devel/drivers/base/Makefile~export-cpu-topology-by-sysfs 2006-01-25 10:57:27.000000000 -0800 +++ devel-akpm/drivers/base/Makefile 2006-01-25 10:57:27.000000000 -0800 @@ -8,6 +8,7 @@ obj-y += power/ obj-$(CONFIG_FW_LOADER) += firmware_class.o obj-$(CONFIG_NUMA) += node.o obj-$(CONFIG_MEMORY_HOTPLUG) += memory.o +obj-$(CONFIG_SMP) += topology.o ifeq ($(CONFIG_DEBUG_DRIVER),y) EXTRA_CFLAGS += -DDEBUG diff -puN /dev/null drivers/base/topology.c --- /dev/null 2003-09-15 06:40:47.000000000 -0700 +++ devel-akpm/drivers/base/topology.c 2006-01-25 10:57:27.000000000 -0800 @@ -0,0 +1,148 @@ +/* + * driver/base/topology.c - Populate sysfs with cpu topology information + * + * Written by: Zhang Yanmin, Intel Corporation + * + * Copyright (C) 2006, Intel Corp. + * + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for more + * details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ +#include +#include +#include +#include +#include +#include + +#define define_one_ro(_name) \ +static SYSDEV_ATTR(_name, 0444, show_##_name, NULL) + +#define define_id_show_func(name) \ +static ssize_t show_##name(struct sys_device *dev, char *buf) \ +{ \ + unsigned int cpu = dev->id; \ + return sprintf(buf, "%d\n", topology_##name(cpu)); \ +} + +#define define_siblings_show_func(name) \ +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)); \ + 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 + NULL +}; + +static struct attribute_group topology_attr_group = { + .attrs = default_attrs, + .name = "topology" +}; + +/* Add/Remove cpu_topology interface for CPU device */ +static int __cpuinit topology_add_dev(struct sys_device * sys_dev) +{ + sysfs_create_group(&sys_dev->kobj, &topology_attr_group); + return 0; +} + +static int __cpuinit topology_remove_dev(struct sys_device * sys_dev) +{ + sysfs_remove_group(&sys_dev->kobj, &topology_attr_group); + return 0; +} + +static int __cpuinit topology_cpu_callback(struct notifier_block *nfb, + unsigned long action, void *hcpu) +{ + unsigned int cpu = (unsigned long)hcpu; + struct sys_device *sys_dev; + + sys_dev = get_cpu_sysdev(cpu); + switch (action) { + case CPU_ONLINE: + topology_add_dev(sys_dev); + break; + case CPU_DEAD: + topology_remove_dev(sys_dev); + break; + } + return NOTIFY_OK; +} + +static struct notifier_block topology_cpu_notifier = +{ + .notifier_call = topology_cpu_callback, +}; + +static int __cpuinit topology_sysfs_init(void) +{ + int i; + + for_each_online_cpu(i) { + topology_cpu_callback(&topology_cpu_notifier, CPU_ONLINE, + (void *)(long)i); + } + + register_cpu_notifier(&topology_cpu_notifier); + + return 0; +} + +device_initcall(topology_sysfs_init); + diff -puN include/asm-i386/topology.h~export-cpu-topology-by-sysfs include/asm-i386/topology.h --- devel/include/asm-i386/topology.h~export-cpu-topology-by-sysfs 2006-01-25 10:57:27.000000000 -0800 +++ devel-akpm/include/asm-i386/topology.h 2006-01-25 10:57:27.000000000 -0800 @@ -27,6 +27,15 @@ #ifndef _ASM_I386_TOPOLOGY_H #define _ASM_I386_TOPOLOGY_H +#ifdef CONFIG_SMP +#define topology_physical_package_id(cpu) \ + ((int)(phys_proc_id[cpu] == BAD_APICID ? -1 : phys_proc_id[cpu])) +#define topology_core_id(cpu) \ + ((int)(cpu_core_id[cpu] == BAD_APICID ? 0 : cpu_core_id[cpu])) +#define topology_core_siblings(cpu) cpu_core_map[cpu] +#define topology_thread_siblings(cpu) cpu_sibling_map[cpu] +#endif + #ifdef CONFIG_NUMA #include diff -puN include/asm-ia64/topology.h~export-cpu-topology-by-sysfs include/asm-ia64/topology.h --- devel/include/asm-ia64/topology.h~export-cpu-topology-by-sysfs 2006-01-25 10:57:27.000000000 -0800 +++ devel-akpm/include/asm-ia64/topology.h 2006-01-25 10:57:27.000000000 -0800 @@ -102,6 +102,13 @@ void build_cpu_to_node_map(void); #endif /* CONFIG_NUMA */ +#ifdef CONFIG_SMP +#define topology_physical_package_id(cpu) cpu_data(cpu)->socket_id +#define topology_core_id(cpu) cpu_data(cpu)->core_id +#define topology_core_siblings(cpu) cpu_core_map[cpu] +#define topology_thread_siblings(cpu) cpu_sibling_map[cpu] +#endif + #include #endif /* _ASM_IA64_TOPOLOGY_H */ diff -puN include/asm-x86_64/topology.h~export-cpu-topology-by-sysfs include/asm-x86_64/topology.h --- devel/include/asm-x86_64/topology.h~export-cpu-topology-by-sysfs 2006-01-25 10:57:27.000000000 -0800 +++ devel-akpm/include/asm-x86_64/topology.h 2006-01-25 10:57:27.000000000 -0800 @@ -57,6 +57,15 @@ extern int __node_distance(int, int); #endif +#ifdef CONFIG_SMP +#define topology_physical_package_id(cpu) \ + ((int)(phys_proc_id[cpu] == BAD_APICID ? -1 : phys_proc_id[cpu])) +#define topology_core_id(cpu) \ + ((int)(cpu_core_id[cpu] == BAD_APICID ? 0 : cpu_core_id[cpu])) +#define topology_core_siblings(cpu) cpu_core_map[cpu] +#define topology_thread_siblings(cpu) cpu_sibling_map[cpu] +#endif + #include #endif _