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[PATCH] Export cpu topology in sysfs

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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 <yanmin.zhang@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Zhang, Yanmin 2006-02-03 03:04:36 -08:00 committed by Linus Torvalds
parent 66ac5a294d
commit 69dcc99199
7 changed files with 225 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

41
Documentation/cputopology.txt Normal file
View file

@ -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.

18
arch/ia64/kernel/topology.c
View file

@ -71,31 +71,33 @@ static int __init topology_init(void)
int i, err = 0;
#ifdef CONFIG_NUMA
sysfs_nodes = kmalloc(sizeof(struct node) * MAX_NUMNODES, GFP_KERNEL);
sysfs_nodes = kzalloc(sizeof(struct node) * MAX_NUMNODES, GFP_KERNEL);
if (!sysfs_nodes) {
err = -ENOMEM;
goto out;
}
memset(sysfs_nodes, 0, sizeof(struct node) * MAX_NUMNODES);
/* MCD - Do we want to register all ONLINE nodes, or all POSSIBLE nodes? */
for_each_online_node(i)
/*
* MCD - Do we want to register all ONLINE nodes, or all POSSIBLE nodes?
*/
for_each_online_node(i) {
if ((err = register_node(&sysfs_nodes[i], i, 0)))
goto out;
}
#endif
sysfs_cpus = kmalloc(sizeof(struct ia64_cpu) * NR_CPUS, GFP_KERNEL);
sysfs_cpus = kzalloc(sizeof(struct ia64_cpu) * NR_CPUS, GFP_KERNEL);
if (!sysfs_cpus) {
err = -ENOMEM;
goto out;
}
memset(sysfs_cpus, 0, sizeof(struct ia64_cpu) * NR_CPUS);
for_each_present_cpu(i)
for_each_present_cpu(i) {
if((err = arch_register_cpu(i)))
goto out;
}
out:
return err;
}
__initcall(topology_init);
subsys_initcall(topology_init);

1
drivers/base/Makefile
View file

@ -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

148
drivers/base/topology.c Normal file
View file

@ -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 <linux/sysdev.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/topology.h>
#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);

9
include/asm-i386/topology.h
View file

@ -27,6 +27,15 @@
#ifndef _ASM_I386_TOPOLOGY_H
#define _ASM_I386_TOPOLOGY_H
#ifdef CONFIG_SMP
#define topology_physical_package_id(cpu) \
(phys_proc_id[cpu] == BAD_APICID ? -1 : phys_proc_id[cpu])
#define topology_core_id(cpu) \
(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 <asm/mpspec.h>

7
include/asm-ia64/topology.h
View file

@ -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 <asm-generic/topology.h>
#endif /* _ASM_IA64_TOPOLOGY_H */

9
include/asm-x86_64/topology.h
View file

@ -57,6 +57,15 @@ extern int __node_distance(int, int);
#endif
#ifdef CONFIG_SMP
#define topology_physical_package_id(cpu) \
(phys_proc_id[cpu] == BAD_APICID ? -1 : phys_proc_id[cpu])
#define topology_core_id(cpu) \
(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 <asm-generic/topology.h>
#endif