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* RE: [PATCH v3]Export cpu topology by sysfs
@ 2006-01-25  2:05 Zhang, Yanmin
  2006-01-25  2:34 ` Yanmin Zhang
  2006-01-26  5:11 ` Nathan Lynch
  0 siblings, 2 replies; 6+ messages in thread
From: Zhang, Yanmin @ 2006-01-25  2:05 UTC (permalink / raw)
  To: Nathan Lynch, Andrew Morton
  Cc: linux-kernel, greg, discuss, linux-ia64, Siddha, Suresh B, Shah,
	Rajesh, Pallipadi, Venkatesh, Yanmin Zhang

>>-----Original Message-----
>>From: linux-ia64-owner@vger.kernel.org [mailto:linux-ia64-owner@vger.kernel.org] On Behalf Of Zhang, Yanmin
>>Sent: 2006年1月9日 14:48
>>To: Nathan Lynch; Yanmin Zhang
>>Cc: linux-kernel@vger.kernel.org; greg@kroah.com; discuss@x86-64.org; linux-ia64@vger.kernel.org; Siddha, Suresh B; Shah, Rajesh;
>>Pallipadi, Venkatesh
>>Subject: RE: [PATCH v3]Export cpu topology by sysfs
>>
>>>>-----Original Message-----
>>>>From: linux-ia64-owner@vger.kernel.org [mailto:linux-ia64-owner@vger.kernel.org] On Behalf Of Nathan Lynch
>>>>Sent: 2006年1月9日 13:10
>>>>To: Yanmin Zhang
>>>>Cc: linux-kernel@vger.kernel.org; greg@kroah.com; discuss@x86-64.org; linux-ia64@vger.kernel.org; Siddha, Suresh B; Shah, Rajesh;
>>>>Pallipadi, Venkatesh
>>>>Subject: Re: [PATCH v3]Export cpu topology by sysfs
>>>>> 2) Set consistent default values for the 4 attributes.
>>>>>
>>>>
>>>><snip>
>>>>
>>>>> 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.
>>>>
>>>>Why not -1 as with the physical package id?  0 could be a valid core
>>>>id.
>>If the cpu has only 1 core, we could call it single-core, so it's reasonable to use 0 as its core id.
>>
>>
>>>>
>>>>> 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.
>>>>
>>>>Really, I think the least confusing interface would not export those
>>>>attributes which are not relevant for the system.  E.g. if the system
>>>>isn't multi-core, you don't see core_id and core_siblings attributes.
>>>>
>>>>Failing that, let's at least have consistent, unambiguous values for
>>>>the ids which are not applicable.
>>Current kernel will output core id by /proc/cpuinfo if a physical cpu has 2 threads, no matter if it's a multi-core, or just a multi-thread.
>>To be consistent with /proc/cpuinfo, I think we need export core id and its default value is 0.
>>
>>>>
>>>><snip>
>>>>> +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;
>>>>> +}
>>>>
>>>>I still oppose this bit.  I want the attributes there for powerpc even
>>>>for offline cpus -- the topology information (if obtainable, which it
>>>>is on powerpc) is useful regardless of the cpu's online state.  The
>>>>attributes should appear when a cpu is made present, and go away when
>>>>a cpu is removed.
>>As my previous email says, there are concerns/issues to do so. A compromise is that the patch could register a sysdev driver. When the
>>cpu becomes offline from online, we don't delete the topology kobj. The compromise has a defect. If the cpu is never online since machine
>>boots, the topology info of the cpu is incorrect.
>>
>>>>
>>>>This week I'll try to do an implementation for powerpc.
Nathan,

Is your implementation for powerpc ready?

Andrew,
Could the patch of version 3 be put into mm tree firstly?

Thanks,
Yanmin


^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH v3]Export cpu topology by sysfs
  2006-01-25  2:05 [PATCH v3]Export cpu topology by sysfs Zhang, Yanmin
@ 2006-01-25  2:34 ` Yanmin Zhang
  2006-01-26  5:11 ` Nathan Lynch
  1 sibling, 0 replies; 6+ messages in thread
From: Yanmin Zhang @ 2006-01-25  2:34 UTC (permalink / raw)
  To: Nathan Lynch, Andrew Morton
  Cc: linux-kernel, greg, discuss, linux-ia64, Siddha, Suresh B, Shah,
	Rajesh, Pallipadi, Venkatesh, yanmin.zhang

Resend the patch and comments because guys might miss it.

---Detailed descriptions---
From: Zhang, Yanmin <yanmin.zhang@intel.com>

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 against 2.6.15-rc5 provides defines for i386/x86_64/ia64.

Signed-off-by: Zhang, Yanmin <yanmin.zhang@intel.com>

---

diff -Nraup linux-2.6.15-rc5/arch/ia64/kernel/topology.c linux-2.6.15-rc5_topology/arch/ia64/kernel/topology.c
--- linux-2.6.15-rc5/arch/ia64/kernel/topology.c	2005-11-07 02:34:06.000000000 +0800
+++ linux-2.6.15-rc5_topology/arch/ia64/kernel/topology.c	2006-01-03 22:54:40.000000000 +0800
@@ -98,4 +98,4 @@ out:
 	return err;
 }
 
-__initcall(topology_init);
+subsys_initcall(topology_init);
diff -Nraup linux-2.6.15-rc5/Documentation/cputopology.txt linux-2.6.15-rc5_topology/Documentation/cputopology.txt
--- linux-2.6.15-rc5/Documentation/cputopology.txt	1970-01-01 08:00:00.000000000 +0800
+++ linux-2.6.15-rc5_topology/Documentation/cputopology.txt	2006-01-04 00:54:38.000000000 +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 -Nraup linux-2.6.15-rc5/drivers/base/Makefile linux-2.6.15-rc5_topology/drivers/base/Makefile
--- linux-2.6.15-rc5/drivers/base/Makefile	2005-12-13 23:07:35.000000000 +0800
+++ linux-2.6.15-rc5_topology/drivers/base/Makefile	2006-01-03 22:54:40.000000000 +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 -Nraup linux-2.6.15-rc5/drivers/base/topology.c linux-2.6.15-rc5_topology/drivers/base/topology.c
--- linux-2.6.15-rc5/drivers/base/topology.c	1970-01-01 08:00:00.000000000 +0800
+++ linux-2.6.15-rc5_topology/drivers/base/topology.c	2006-01-04 00:54:48.000000000 +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 <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);
+
diff -Nraup linux-2.6.15-rc5/include/asm-i386/topology.h linux-2.6.15-rc5_topology/include/asm-i386/topology.h
--- linux-2.6.15-rc5/include/asm-i386/topology.h	2005-11-07 02:34:08.000000000 +0800
+++ linux-2.6.15-rc5_topology/include/asm-i386/topology.h	2006-01-04 00:16:13.000000000 +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 <asm/mpspec.h>
diff -Nraup linux-2.6.15-rc5/include/asm-ia64/topology.h linux-2.6.15-rc5_topology/include/asm-ia64/topology.h
--- linux-2.6.15-rc5/include/asm-ia64/topology.h	2005-11-07 02:34:08.000000000 +0800
+++ linux-2.6.15-rc5_topology/include/asm-ia64/topology.h	2006-01-04 00:07:47.000000000 +0800
@@ -100,6 +100,13 @@ 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 */
diff -Nraup linux-2.6.15-rc5/include/asm-x86_64/topology.h linux-2.6.15-rc5_topology/include/asm-x86_64/topology.h
--- linux-2.6.15-rc5/include/asm-x86_64/topology.h	2005-12-13 23:07:39.000000000 +0800
+++ linux-2.6.15-rc5_topology/include/asm-x86_64/topology.h	2006-01-04 00:14:22.000000000 +0800
@@ -58,6 +58,15 @@ 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 <asm-generic/topology.h>
 
 #endif

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH v3]Export cpu topology by sysfs
  2006-01-25  2:05 [PATCH v3]Export cpu topology by sysfs Zhang, Yanmin
  2006-01-25  2:34 ` Yanmin Zhang
@ 2006-01-26  5:11 ` Nathan Lynch
  1 sibling, 0 replies; 6+ messages in thread
From: Nathan Lynch @ 2006-01-26  5:11 UTC (permalink / raw)
  To: Zhang, Yanmin
  Cc: Andrew Morton, linux-kernel, greg, discuss, linux-ia64, Siddha,
	Suresh B, Shah, Rajesh, Pallipadi, Venkatesh, Yanmin Zhang

Zhang, Yanmin wrote:
> >>>>This week I'll try to do an implementation for powerpc.

> Is your implementation for powerpc ready?

No, I've been too busy with other things, sorry.

^ permalink raw reply	[flat|nested] 6+ messages in thread
* RE: [PATCH v3]Export cpu topology by sysfs
@ 2006-01-09  6:47 Zhang, Yanmin
  0 siblings, 0 replies; 6+ messages in thread
From: Zhang, Yanmin @ 2006-01-09  6:47 UTC (permalink / raw)
  To: Nathan Lynch, Yanmin Zhang
  Cc: linux-kernel, greg, discuss, linux-ia64, Siddha, Suresh B, Shah,
	Rajesh, Pallipadi, Venkatesh

>>-----Original Message-----
>>From: linux-ia64-owner@vger.kernel.org [mailto:linux-ia64-owner@vger.kernel.org] On Behalf Of Nathan Lynch
>>Sent: 2006年1月9日 13:10
>>To: Yanmin Zhang
>>Cc: linux-kernel@vger.kernel.org; greg@kroah.com; discuss@x86-64.org; linux-ia64@vger.kernel.org; Siddha, Suresh B; Shah, Rajesh;
>>Pallipadi, Venkatesh
>>Subject: Re: [PATCH v3]Export cpu topology by sysfs
>>> 2) Set consistent default values for the 4 attributes.
>>>
>>
>><snip>
>>
>>> 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.
>>
>>Why not -1 as with the physical package id?  0 could be a valid core
>>id.
If the cpu has only 1 core, we could call it single-core, so it's reasonable to use 0 as its core id.


>>
>>> 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.
>>
>>Really, I think the least confusing interface would not export those
>>attributes which are not relevant for the system.  E.g. if the system
>>isn't multi-core, you don't see core_id and core_siblings attributes.
>>
>>Failing that, let's at least have consistent, unambiguous values for
>>the ids which are not applicable.
Current kernel will output core id by /proc/cpuinfo if a physical cpu has 2 threads, no matter if it's a multi-core, or just a multi-thread. To be consistent with /proc/cpuinfo, I think we need export core id and its default value is 0.

>>
>><snip>
>>> +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;
>>> +}
>>
>>I still oppose this bit.  I want the attributes there for powerpc even
>>for offline cpus -- the topology information (if obtainable, which it
>>is on powerpc) is useful regardless of the cpu's online state.  The
>>attributes should appear when a cpu is made present, and go away when
>>a cpu is removed.
As my previous email says, there are concerns/issues to do so. A compromise is that the patch could register a sysdev driver. When the cpu becomes offline from online, we don't delete the topology kobj. The compromise has a defect. If the cpu is never online since machine boots, the topology info of the cpu is incorrect. 

>>
>>This week I'll try to do an implementation for powerpc.

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH v3]Export cpu topology by sysfs
  2006-01-04  9:06 ` [PATCH v3]Export " Yanmin Zhang
@ 2006-01-09  5:10   ` Nathan Lynch
  0 siblings, 0 replies; 6+ messages in thread
From: Nathan Lynch @ 2006-01-09  5:10 UTC (permalink / raw)
  To: Yanmin Zhang
  Cc: linux-kernel, greg, discuss, linux-ia64, Siddha, Suresh B, Shah,
	Rajesh, Pallipadi, Venkatesh

(sorry for the delay in response)

Yanmin Zhang wrote:
> Here is version 3. Based on Nathan's comments, the main changes are:
> 1) Drop thread id, so the first 2 patches of version 2 are dropped;

Thanks.

> 2) Set consistent default values for the 4 attributes.
> 

<snip>

> 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.

Why not -1 as with the physical package id?  0 could be a valid core
id.

> 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.

Really, I think the least confusing interface would not export those
attributes which are not relevant for the system.  E.g. if the system
isn't multi-core, you don't see core_id and core_siblings attributes.

Failing that, let's at least have consistent, unambiguous values for
the ids which are not applicable.

<snip>
> +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;
> +}

I still oppose this bit.  I want the attributes there for powerpc even
for offline cpus -- the topology information (if obtainable, which it
is on powerpc) is useful regardless of the cpu's online state.  The
attributes should appear when a cpu is made present, and go away when
a cpu is removed.

This week I'll try to do an implementation for powerpc.

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH v3]Export cpu topology by sysfs
  2005-12-31  8:43 [PATCH v2:3/3]Export " Zhang, Yanmin
@ 2006-01-04  9:06 ` Yanmin Zhang
  2006-01-09  5:10   ` Nathan Lynch
  0 siblings, 1 reply; 6+ messages in thread
From: Yanmin Zhang @ 2006-01-04  9:06 UTC (permalink / raw)
  To: linux-kernel
  Cc: Nathan Lynch, greg, discuss, linux-ia64, Siddha, Suresh B, Shah,
	Rajesh, Pallipadi, Venkatesh

Here is version 3. Based on Nathan's comments, the main changes are:
1) Drop thread id, so the first 2 patches of version 2 are dropped;
2) Set consistent default values for the 4 attributes.

---Detailed descriptions---
From: Zhang, Yanmin <yanmin.zhang@intel.com>

The 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_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 against 2.6.15-rc5 provides defines for i386/x86_64/ia64.

Signed-off-by: Zhang, Yanmin <yanmin.zhang@intel.com>

---

diff -Nraup linux-2.6.15-rc5/arch/ia64/kernel/topology.c linux-2.6.15-rc5_topology/arch/ia64/kernel/topology.c
--- linux-2.6.15-rc5/arch/ia64/kernel/topology.c	2005-11-07 02:34:06.000000000 +0800
+++ linux-2.6.15-rc5_topology/arch/ia64/kernel/topology.c	2006-01-03 22:54:40.000000000 +0800
@@ -98,4 +98,4 @@ out:
 	return err;
 }
 
-__initcall(topology_init);
+subsys_initcall(topology_init);
diff -Nraup linux-2.6.15-rc5/Documentation/cputopology.txt linux-2.6.15-rc5_topology/Documentation/cputopology.txt
--- linux-2.6.15-rc5/Documentation/cputopology.txt	1970-01-01 08:00:00.000000000 +0800
+++ linux-2.6.15-rc5_topology/Documentation/cputopology.txt	2006-01-04 00:54:38.000000000 +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 -Nraup linux-2.6.15-rc5/drivers/base/Makefile linux-2.6.15-rc5_topology/drivers/base/Makefile
--- linux-2.6.15-rc5/drivers/base/Makefile	2005-12-13 23:07:35.000000000 +0800
+++ linux-2.6.15-rc5_topology/drivers/base/Makefile	2006-01-03 22:54:40.000000000 +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 -Nraup linux-2.6.15-rc5/drivers/base/topology.c linux-2.6.15-rc5_topology/drivers/base/topology.c
--- linux-2.6.15-rc5/drivers/base/topology.c	1970-01-01 08:00:00.000000000 +0800
+++ linux-2.6.15-rc5_topology/drivers/base/topology.c	2006-01-04 00:54:48.000000000 +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 <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);
+
diff -Nraup linux-2.6.15-rc5/include/asm-i386/topology.h linux-2.6.15-rc5_topology/include/asm-i386/topology.h
--- linux-2.6.15-rc5/include/asm-i386/topology.h	2005-11-07 02:34:08.000000000 +0800
+++ linux-2.6.15-rc5_topology/include/asm-i386/topology.h	2006-01-04 00:16:13.000000000 +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 <asm/mpspec.h>
diff -Nraup linux-2.6.15-rc5/include/asm-ia64/topology.h linux-2.6.15-rc5_topology/include/asm-ia64/topology.h
--- linux-2.6.15-rc5/include/asm-ia64/topology.h	2005-11-07 02:34:08.000000000 +0800
+++ linux-2.6.15-rc5_topology/include/asm-ia64/topology.h	2006-01-04 00:07:47.000000000 +0800
@@ -100,6 +100,13 @@ 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 */
diff -Nraup linux-2.6.15-rc5/include/asm-x86_64/topology.h linux-2.6.15-rc5_topology/include/asm-x86_64/topology.h
--- linux-2.6.15-rc5/include/asm-x86_64/topology.h	2005-12-13 23:07:39.000000000 +0800
+++ linux-2.6.15-rc5_topology/include/asm-x86_64/topology.h	2006-01-04 00:14:22.000000000 +0800
@@ -58,6 +58,15 @@ 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 <asm-generic/topology.h>
 
 #endif

^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2006-01-26  5:11 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2006-01-25  2:05 [PATCH v3]Export cpu topology by sysfs Zhang, Yanmin
2006-01-25  2:34 ` Yanmin Zhang
2006-01-26  5:11 ` Nathan Lynch
  -- strict thread matches above, loose matches on Subject: below --
2006-01-09  6:47 Zhang, Yanmin
2005-12-31  8:43 [PATCH v2:3/3]Export " Zhang, Yanmin
2006-01-04  9:06 ` [PATCH v3]Export " Yanmin Zhang
2006-01-09  5:10   ` Nathan Lynch

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