Export cpu topology by sysfs
Subsystems (2)
PATCH 1/1 Export cpu topology by sysfs
From: Zhang, Yanmin <[email protected]>
The third patch implements the 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_id:
represent the cpu thread id to cpu X;
4) /sys/devices/system/cpu/cpuX/topology/thread_siblings:
represent the thread siblings to cpu X in the same core;
5) /sys/devices/system/cpu/cpuX/topology/core_siblings:
represent the thread siblings to cpu X in the same physical package;
If one architecture wants to support this feature, it just needs to implement 5 defines, typically in file include/asm-XXX/topology.h. The 5 defines are:
#define topology_physical_package_id(cpu)
#define topology_core_id(cpu)
#define topology_thread_id(cpu)
#define topology_thread_siblings(cpu)
#define topology_core_siblings(cpu)
The type of siblings is cpumask_t.
If an attribute isn't defined on an architecture, it won't be exported.
The patch against 2.6.15-rc5 provides defines for i386/x86_64/ia64.
#diffstat export_topology_2.6.15-rc5_v4.patch
Documentation/cputopology.txt | 31 ++++++ arch/ia64/kernel/topology.c | 2 drivers/base/Makefile | 1 drivers/base/topology.c | 201 ++++++++++++++++++++++++++++++++++++++++++ include/asm-i386/topology.h | 8 + include/asm-ia64/topology.h | 8 + include/asm-x86_64/topology.h | 8 + 7 files changed, 258 insertions, 1 deletion
---
arch/ia64/kernel/topology.c +1 -1
@@ -98,4 +98,4 @@ out:return err; } -__initcall (topology_init); +subsys_initcall (topology_init);
Documentation/cputopology.txt +31 -0
@@ -0,0 +1,31 @@ + +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_id: +represent the cpu thread id to cpu X; +4) /sys/devices/system/cpu/cpuX/topology/thread_siblings: +represent the thread siblings to cpu X in the same core; +5) /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 5 defines, typically in file include/asm-XXX/topology.h. +The 5 defines are: +#define topology_physical_package_id(cpu) +#define topology_core_id(cpu) +#define topology_thread_id(cpu) +#define topology_thread_siblings(cpu) +#define topology_core_siblings(cpu) + +The type of siblings is cpumask_t. + +If an attribute isn't defined on an architecture, it won't be exported. +
drivers/base/Makefile +1 -0
@@ -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
drivers/base/topology.c +200 -0
200 lines not on this page · raw message
include/asm-i386/topology.h +8 -0
@@ -27,6 +27,14 @@#ifndef _ASM_I386_TOPOLOGY_H#define _ASM_I386_TOPOLOGY_H +#ifdef CONFIG_SMP +#define topology_physical_package_id (cpu) phys_proc_id[cpu] +#define topology_core_id (cpu) cpu_core_id[cpu] +#define topology_thread_id (cpu) cpu_thread_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>
include/asm-ia64/topology.h +8 -0
@@ -100,6 +100,14 @@ 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_thread_id (cpu) cpu_data(cpu)->thread_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 */
include/asm-x86_64/topology.h +8 -0
@@ -58,6 +58,14 @@ extern int __node_distance(int, int);#endif +#ifdef CONFIG_SMP +#define topology_physical_package_id (cpu) phys_proc_id[cpu] +#define topology_core_id (cpu) cpu_core_id[cpu] +#define topology_thread_id (cpu) cpu_thread_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
drivers/base/topology.c line 2
Quoted 5 lines · Yanmin Zhang
drivers/base/topology.c +2
-0@@ -0,0 +1,201 @@ +/* +* driver/base/topology.c - Populate driverfs with cpu topology information
driverfs? Where did you cut/paste this code from?
And why does it have to be in driver/base?
drivers/base/topology.c line 37
Quoted 5 lines
drivers/base/topology.c +5
-0+struct _topology_attr { +struct attribute attr; +ssize_t (*show)(int cpu,char *); +ssize_t (*store)(const char *,size_t count); +};
Don't put a '_' at the beginning of a structure please.
drivers/base/topology.c line 120
Quoted 10 lines
drivers/base/topology.c +10
-0+static ssize_t topology_show (struct kobject * kobj,struct attribute * attr,char * buf) +{ +unsigned int cpu; +struct _topology_attr *fattr =to_attr (attr); +ssize_t ret; + + cpu = container_of(kobj->parent, struct sys_device, kobj)->id; + ret = fattr->show ? fattr->show (cpu, buf):0 ; +return ret; +}
Mix of spaces and tabs :(
drivers/base/topology.c line 126
Quoted 5 lines
drivers/base/topology.c +5
-0+static ssize_t topology_store (struct kobject * kobj,struct attribute * attr, +const char * buf,size_t count) +{ +return 0 ; +}
Why is this function even needed?
Quoted 13 lines
drivers/base/topology.c +13
-0+static struct sysfs_ops topology_sysfs_ops = { + .show = topology_show, + .store = topology_store, +}; + +static struct kobj_type topology_ktype = { + .sysfs_ops = &topology_sysfs_ops, + .default_attrs = topology_default_attrs, +}; + +/* Add/Remove cpu_topology interface for CPU device */ +static int __cpuinit topology_add_dev (struct sys_device * sys_dev) +{
drivers/base/topology.c line 150
Quoted 10 lines
drivers/base/topology.c +10
-0+unsigned int cpu = sys_dev->id; + +memset (&cpu_topology_kobject[cpu],0 ,sizeof (struct kobject )); + + cpu_topology_kobject[cpu].parent = &sys_dev->kobj; +kobject_set_name (&cpu_topology_kobject[cpu],"%s" ,"topology" ); + cpu_topology_kobject[cpu].ktype = &topology_ktype; + +return kobject_register (&cpu_topology_kobject[cpu]); +}
Can't you just use an attribute group and attach it to the cpu kobject? That would save an array of kobjects I think.
Quoted 6 lines
drivers/base/topology.c +6
-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; +
drivers/base/topology.c line 176
Quoted 10 lines
drivers/base/topology.c +10
-0+ sys_dev =get_cpu_sysdev (cpu); +switch (action) { +case CPU_ONLINE : +topology_add_dev (sys_dev); +break ; +#ifdef CONFIG_HOTPLUG_CPU +case CPU_DEAD : +topology_remove_dev (sys_dev); +break ; +#endif
Why ifdef? Isn't it safe to just always have this in?
thanks,
greg k-h