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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
Download Patch File Download Diff File Expand all files Collapse all files

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);