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authorGary Hade <garyhade@us.ibm.com>2009-01-06 14:39:14 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-06 15:59:00 -0800
commitc04fc586c1a480ba198f03ae7b6cbd7b57380b91 (patch)
tree9d6544a3b62cc01dbcbb1e315b84378b45ba86d2
parentee53a891f47444c53318b98dac947ede963db400 (diff)
downloadlwn-c04fc586c1a480ba198f03ae7b6cbd7b57380b91.tar.gz
lwn-c04fc586c1a480ba198f03ae7b6cbd7b57380b91.zip
mm: show node to memory section relationship with symlinks in sysfs
Show node to memory section relationship with symlinks in sysfs Add /sys/devices/system/node/nodeX/memoryY symlinks for all the memory sections located on nodeX. For example: /sys/devices/system/node/node1/memory135 -> ../../memory/memory135 indicates that memory section 135 resides on node1. Also revises documentation to cover this change as well as updating Documentation/ABI/testing/sysfs-devices-memory to include descriptions of memory hotremove files 'phys_device', 'phys_index', and 'state' that were previously not described there. In addition to it always being a good policy to provide users with the maximum possible amount of physical location information for resources that can be hot-added and/or hot-removed, the following are some (but likely not all) of the user benefits provided by this change. Immediate: - Provides information needed to determine the specific node on which a defective DIMM is located. This will reduce system downtime when the node or defective DIMM is swapped out. - Prevents unintended onlining of a memory section that was previously offlined due to a defective DIMM. This could happen during node hot-add when the user or node hot-add assist script onlines _all_ offlined sections due to user or script inability to identify the specific memory sections located on the hot-added node. The consequences of reintroducing the defective memory could be ugly. - Provides information needed to vary the amount and distribution of memory on specific nodes for testing or debugging purposes. Future: - Will provide information needed to identify the memory sections that need to be offlined prior to physical removal of a specific node. Symlink creation during boot was tested on 2-node x86_64, 2-node ppc64, and 2-node ia64 systems. Symlink creation during physical memory hot-add tested on a 2-node x86_64 system. Signed-off-by: Gary Hade <garyhade@us.ibm.com> Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--Documentation/ABI/testing/sysfs-devices-memory51
-rw-r--r--Documentation/memory-hotplug.txt16
-rw-r--r--arch/ia64/mm/init.c2
-rw-r--r--arch/powerpc/mm/mem.c2
-rw-r--r--arch/s390/mm/init.c2
-rw-r--r--arch/sh/mm/init.c3
-rw-r--r--arch/x86/mm/init_32.c2
-rw-r--r--arch/x86/mm/init_64.c2
-rw-r--r--drivers/base/memory.c19
-rw-r--r--drivers/base/node.c103
-rw-r--r--include/linux/memory.h6
-rw-r--r--include/linux/memory_hotplug.h2
-rw-r--r--include/linux/node.h13
-rw-r--r--mm/memory_hotplug.c11
14 files changed, 209 insertions, 25 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory
index 7a16fe1e2270..9fe91c02ee40 100644
--- a/Documentation/ABI/testing/sysfs-devices-memory
+++ b/Documentation/ABI/testing/sysfs-devices-memory
@@ -6,7 +6,6 @@ Description:
internal state of the kernel memory blocks. Files could be
added or removed dynamically to represent hot-add/remove
operations.
-
Users: hotplug memory add/remove tools
https://w3.opensource.ibm.com/projects/powerpc-utils/
@@ -19,6 +18,56 @@ Description:
This is useful for a user-level agent to determine
identify removable sections of the memory before attempting
potentially expensive hot-remove memory operation
+Users: hotplug memory remove tools
+ https://w3.opensource.ibm.com/projects/powerpc-utils/
+
+What: /sys/devices/system/memory/memoryX/phys_device
+Date: September 2008
+Contact: Badari Pulavarty <pbadari@us.ibm.com>
+Description:
+ The file /sys/devices/system/memory/memoryX/phys_device
+ is read-only and is designed to show the name of physical
+ memory device. Implementation is currently incomplete.
+What: /sys/devices/system/memory/memoryX/phys_index
+Date: September 2008
+Contact: Badari Pulavarty <pbadari@us.ibm.com>
+Description:
+ The file /sys/devices/system/memory/memoryX/phys_index
+ is read-only and contains the section ID in hexadecimal
+ which is equivalent to decimal X contained in the
+ memory section directory name.
+
+What: /sys/devices/system/memory/memoryX/state
+Date: September 2008
+Contact: Badari Pulavarty <pbadari@us.ibm.com>
+Description:
+ The file /sys/devices/system/memory/memoryX/state
+ is read-write. When read, it's contents show the
+ online/offline state of the memory section. When written,
+ root can toggle the the online/offline state of a removable
+ memory section (see removable file description above)
+ using the following commands.
+ # echo online > /sys/devices/system/memory/memoryX/state
+ # echo offline > /sys/devices/system/memory/memoryX/state
+
+ For example, if /sys/devices/system/memory/memory22/removable
+ contains a value of 1 and
+ /sys/devices/system/memory/memory22/state contains the
+ string "online" the following command can be executed by
+ by root to offline that section.
+ # echo offline > /sys/devices/system/memory/memory22/state
Users: hotplug memory remove tools
https://w3.opensource.ibm.com/projects/powerpc-utils/
+
+What: /sys/devices/system/node/nodeX/memoryY
+Date: September 2008
+Contact: Gary Hade <garyhade@us.ibm.com>
+Description:
+ When CONFIG_NUMA is enabled
+ /sys/devices/system/node/nodeX/memoryY is a symbolic link that
+ points to the corresponding /sys/devices/system/memory/memoryY
+ memory section directory. For example, the following symbolic
+ link is created for memory section 9 on node0.
+ /sys/devices/system/node/node0/memory9 -> ../../memory/memory9
+
diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt
index 168117bd6ee8..4c2ecf537a4a 100644
--- a/Documentation/memory-hotplug.txt
+++ b/Documentation/memory-hotplug.txt
@@ -124,7 +124,7 @@ config options.
This option can be kernel module too.
--------------------------------
-3 sysfs files for memory hotplug
+4 sysfs files for memory hotplug
--------------------------------
All sections have their device information under /sys/devices/system/memory as
@@ -138,11 +138,12 @@ For example, assume 1GiB section size. A device for a memory starting at
(0x100000000 / 1Gib = 4)
This device covers address range [0x100000000 ... 0x140000000)
-Under each section, you can see 3 files.
+Under each section, you can see 4 files.
/sys/devices/system/memory/memoryXXX/phys_index
/sys/devices/system/memory/memoryXXX/phys_device
/sys/devices/system/memory/memoryXXX/state
+/sys/devices/system/memory/memoryXXX/removable
'phys_index' : read-only and contains section id, same as XXX.
'state' : read-write
@@ -150,10 +151,20 @@ Under each section, you can see 3 files.
at write: user can specify "online", "offline" command
'phys_device': read-only: designed to show the name of physical memory device.
This is not well implemented now.
+'removable' : read-only: contains an integer value indicating
+ whether the memory section is removable or not
+ removable. A value of 1 indicates that the memory
+ section is removable and a value of 0 indicates that
+ it is not removable.
NOTE:
These directories/files appear after physical memory hotplug phase.
+If CONFIG_NUMA is enabled the
+/sys/devices/system/memory/memoryXXX memory section
+directories can also be accessed via symbolic links located in
+the /sys/devices/system/node/node* directories. For example:
+/sys/devices/system/node/node0/memory9 -> ../../memory/memory9
--------------------------------
4. Physical memory hot-add phase
@@ -365,7 +376,6 @@ node if necessary.
- allowing memory hot-add to ZONE_MOVABLE. maybe we need some switch like
sysctl or new control file.
- showing memory section and physical device relationship.
- - showing memory section and node relationship (maybe good for NUMA)
- showing memory section is under ZONE_MOVABLE or not
- test and make it better memory offlining.
- support HugeTLB page migration and offlining.
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 054bcd9439aa..56e12903973c 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -692,7 +692,7 @@ int arch_add_memory(int nid, u64 start, u64 size)
pgdat = NODE_DATA(nid);
zone = pgdat->node_zones + ZONE_NORMAL;
- ret = __add_pages(zone, start_pfn, nr_pages);
+ ret = __add_pages(nid, zone, start_pfn, nr_pages);
if (ret)
printk("%s: Problem encountered in __add_pages() as ret=%d\n",
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 53b06ebb3f2f..f00f09a77f12 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -132,7 +132,7 @@ int arch_add_memory(int nid, u64 start, u64 size)
/* this should work for most non-highmem platforms */
zone = pgdata->node_zones;
- return __add_pages(zone, start_pfn, nr_pages);
+ return __add_pages(nid, zone, start_pfn, nr_pages);
}
#endif /* CONFIG_MEMORY_HOTPLUG */
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 158b0d6d7046..f0258ca3b17e 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -183,7 +183,7 @@ int arch_add_memory(int nid, u64 start, u64 size)
rc = vmem_add_mapping(start, size);
if (rc)
return rc;
- rc = __add_pages(zone, PFN_DOWN(start), PFN_DOWN(size));
+ rc = __add_pages(nid, zone, PFN_DOWN(start), PFN_DOWN(size));
if (rc)
vmem_remove_mapping(start, size);
return rc;
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 6cbef8caeb56..3edf297c829b 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -311,7 +311,8 @@ int arch_add_memory(int nid, u64 start, u64 size)
pgdat = NODE_DATA(nid);
/* We only have ZONE_NORMAL, so this is easy.. */
- ret = __add_pages(pgdat->node_zones + ZONE_NORMAL, start_pfn, nr_pages);
+ ret = __add_pages(nid, pgdat->node_zones + ZONE_NORMAL,
+ start_pfn, nr_pages);
if (unlikely(ret))
printk("%s: Failed, __add_pages() == %d\n", __func__, ret);
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index f99a6c6c432e..544d724caeee 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -1079,7 +1079,7 @@ int arch_add_memory(int nid, u64 start, u64 size)
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
- return __add_pages(zone, start_pfn, nr_pages);
+ return __add_pages(nid, zone, start_pfn, nr_pages);
}
#endif
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 9f7a0d24d42a..54c437e96541 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -857,7 +857,7 @@ int arch_add_memory(int nid, u64 start, u64 size)
if (last_mapped_pfn > max_pfn_mapped)
max_pfn_mapped = last_mapped_pfn;
- ret = __add_pages(zone, start_pfn, nr_pages);
+ ret = __add_pages(nid, zone, start_pfn, nr_pages);
WARN_ON_ONCE(ret);
return ret;
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 5260e9e0df48..989429cfed88 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -347,8 +347,9 @@ static inline int memory_probe_init(void)
* section belongs to...
*/
-static int add_memory_block(unsigned long node_id, struct mem_section *section,
- unsigned long state, int phys_device)
+static int add_memory_block(int nid, struct mem_section *section,
+ unsigned long state, int phys_device,
+ enum mem_add_context context)
{
struct memory_block *mem = kzalloc(sizeof(*mem), GFP_KERNEL);
int ret = 0;
@@ -370,6 +371,10 @@ static int add_memory_block(unsigned long node_id, struct mem_section *section,
ret = mem_create_simple_file(mem, phys_device);
if (!ret)
ret = mem_create_simple_file(mem, removable);
+ if (!ret) {
+ if (context == HOTPLUG)
+ ret = register_mem_sect_under_node(mem, nid);
+ }
return ret;
}
@@ -382,7 +387,7 @@ static int add_memory_block(unsigned long node_id, struct mem_section *section,
*
* This could be made generic for all sysdev classes.
*/
-static struct memory_block *find_memory_block(struct mem_section *section)
+struct memory_block *find_memory_block(struct mem_section *section)
{
struct kobject *kobj;
struct sys_device *sysdev;
@@ -411,6 +416,7 @@ int remove_memory_block(unsigned long node_id, struct mem_section *section,
struct memory_block *mem;
mem = find_memory_block(section);
+ unregister_mem_sect_under_nodes(mem);
mem_remove_simple_file(mem, phys_index);
mem_remove_simple_file(mem, state);
mem_remove_simple_file(mem, phys_device);
@@ -424,9 +430,9 @@ int remove_memory_block(unsigned long node_id, struct mem_section *section,
* need an interface for the VM to add new memory regions,
* but without onlining it.
*/
-int register_new_memory(struct mem_section *section)
+int register_new_memory(int nid, struct mem_section *section)
{
- return add_memory_block(0, section, MEM_OFFLINE, 0);
+ return add_memory_block(nid, section, MEM_OFFLINE, 0, HOTPLUG);
}
int unregister_memory_section(struct mem_section *section)
@@ -458,7 +464,8 @@ int __init memory_dev_init(void)
for (i = 0; i < NR_MEM_SECTIONS; i++) {
if (!present_section_nr(i))
continue;
- err = add_memory_block(0, __nr_to_section(i), MEM_ONLINE, 0);
+ err = add_memory_block(0, __nr_to_section(i), MEM_ONLINE,
+ 0, BOOT);
if (!ret)
ret = err;
}
diff --git a/drivers/base/node.c b/drivers/base/node.c
index 91636cd8b6c9..43fa90b837ee 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -6,6 +6,7 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
+#include <linux/memory.h>
#include <linux/node.h>
#include <linux/hugetlb.h>
#include <linux/cpumask.h>
@@ -248,6 +249,105 @@ int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
return 0;
}
+#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
+#define page_initialized(page) (page->lru.next)
+
+static int get_nid_for_pfn(unsigned long pfn)
+{
+ struct page *page;
+
+ if (!pfn_valid_within(pfn))
+ return -1;
+ page = pfn_to_page(pfn);
+ if (!page_initialized(page))
+ return -1;
+ return pfn_to_nid(pfn);
+}
+
+/* register memory section under specified node if it spans that node */
+int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
+{
+ unsigned long pfn, sect_start_pfn, sect_end_pfn;
+
+ if (!mem_blk)
+ return -EFAULT;
+ if (!node_online(nid))
+ return 0;
+ sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
+ sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
+ for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
+ int page_nid;
+
+ page_nid = get_nid_for_pfn(pfn);
+ if (page_nid < 0)
+ continue;
+ if (page_nid != nid)
+ continue;
+ return sysfs_create_link_nowarn(&node_devices[nid].sysdev.kobj,
+ &mem_blk->sysdev.kobj,
+ kobject_name(&mem_blk->sysdev.kobj));
+ }
+ /* mem section does not span the specified node */
+ return 0;
+}
+
+/* unregister memory section under all nodes that it spans */
+int unregister_mem_sect_under_nodes(struct memory_block *mem_blk)
+{
+ nodemask_t unlinked_nodes;
+ unsigned long pfn, sect_start_pfn, sect_end_pfn;
+
+ if (!mem_blk)
+ return -EFAULT;
+ nodes_clear(unlinked_nodes);
+ sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
+ sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
+ for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
+ unsigned int nid;
+
+ nid = get_nid_for_pfn(pfn);
+ if (nid < 0)
+ continue;
+ if (!node_online(nid))
+ continue;
+ if (node_test_and_set(nid, unlinked_nodes))
+ continue;
+ sysfs_remove_link(&node_devices[nid].sysdev.kobj,
+ kobject_name(&mem_blk->sysdev.kobj));
+ }
+ return 0;
+}
+
+static int link_mem_sections(int nid)
+{
+ unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
+ unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
+ unsigned long pfn;
+ int err = 0;
+
+ for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
+ unsigned long section_nr = pfn_to_section_nr(pfn);
+ struct mem_section *mem_sect;
+ struct memory_block *mem_blk;
+ int ret;
+
+ if (!present_section_nr(section_nr))
+ continue;
+ mem_sect = __nr_to_section(section_nr);
+ mem_blk = find_memory_block(mem_sect);
+ ret = register_mem_sect_under_node(mem_blk, nid);
+ if (!err)
+ err = ret;
+
+ /* discard ref obtained in find_memory_block() */
+ kobject_put(&mem_blk->sysdev.kobj);
+ }
+ return err;
+}
+#else
+static int link_mem_sections(int nid) { return 0; }
+#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
+
int register_one_node(int nid)
{
int error = 0;
@@ -267,6 +367,9 @@ int register_one_node(int nid)
if (cpu_to_node(cpu) == nid)
register_cpu_under_node(cpu, nid);
}
+
+ /* link memory sections under this node */
+ error = link_mem_sections(nid);
}
return error;
diff --git a/include/linux/memory.h b/include/linux/memory.h
index 36c82c9e6ea7..3fdc10806d31 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -79,14 +79,14 @@ static inline int memory_notify(unsigned long val, void *v)
#else
extern int register_memory_notifier(struct notifier_block *nb);
extern void unregister_memory_notifier(struct notifier_block *nb);
-extern int register_new_memory(struct mem_section *);
+extern int register_new_memory(int, struct mem_section *);
extern int unregister_memory_section(struct mem_section *);
extern int memory_dev_init(void);
extern int remove_memory_block(unsigned long, struct mem_section *, int);
extern int memory_notify(unsigned long val, void *v);
+extern struct memory_block *find_memory_block(struct mem_section *);
#define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT)
-
-
+enum mem_add_context { BOOT, HOTPLUG };
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
#ifdef CONFIG_MEMORY_HOTPLUG
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 763ba81fc0f0..d95f72e79b82 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -72,7 +72,7 @@ extern void __offline_isolated_pages(unsigned long, unsigned long);
extern int offline_pages(unsigned long, unsigned long, unsigned long);
/* reasonably generic interface to expand the physical pages in a zone */
-extern int __add_pages(struct zone *zone, unsigned long start_pfn,
+extern int __add_pages(int nid, struct zone *zone, unsigned long start_pfn,
unsigned long nr_pages);
extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
unsigned long nr_pages);
diff --git a/include/linux/node.h b/include/linux/node.h
index bc001bc225c3..681a697b9a86 100644
--- a/include/linux/node.h
+++ b/include/linux/node.h
@@ -26,6 +26,7 @@ struct node {
struct sys_device sysdev;
};
+struct memory_block;
extern struct node node_devices[];
extern int register_node(struct node *, int, struct node *);
@@ -35,6 +36,9 @@ extern int register_one_node(int nid);
extern void unregister_one_node(int nid);
extern int register_cpu_under_node(unsigned int cpu, unsigned int nid);
extern int unregister_cpu_under_node(unsigned int cpu, unsigned int nid);
+extern int register_mem_sect_under_node(struct memory_block *mem_blk,
+ int nid);
+extern int unregister_mem_sect_under_nodes(struct memory_block *mem_blk);
#else
static inline int register_one_node(int nid)
{
@@ -52,6 +56,15 @@ static inline int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
{
return 0;
}
+static inline int register_mem_sect_under_node(struct memory_block *mem_blk,
+ int nid)
+{
+ return 0;
+}
+static inline int unregister_mem_sect_under_nodes(struct memory_block *mem_blk)
+{
+ return 0;
+}
#endif
#define to_node(sys_device) container_of(sys_device, struct node, sysdev)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index b17371185468..2ba38bc07b47 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -216,7 +216,8 @@ static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
return 0;
}
-static int __meminit __add_section(struct zone *zone, unsigned long phys_start_pfn)
+static int __meminit __add_section(int nid, struct zone *zone,
+ unsigned long phys_start_pfn)
{
int nr_pages = PAGES_PER_SECTION;
int ret;
@@ -234,7 +235,7 @@ static int __meminit __add_section(struct zone *zone, unsigned long phys_start_p
if (ret < 0)
return ret;
- return register_new_memory(__pfn_to_section(phys_start_pfn));
+ return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
}
#ifdef CONFIG_SPARSEMEM_VMEMMAP
@@ -273,8 +274,8 @@ static int __remove_section(struct zone *zone, struct mem_section *ms)
* call this function after deciding the zone to which to
* add the new pages.
*/
-int __ref __add_pages(struct zone *zone, unsigned long phys_start_pfn,
- unsigned long nr_pages)
+int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
+ unsigned long nr_pages)
{
unsigned long i;
int err = 0;
@@ -284,7 +285,7 @@ int __ref __add_pages(struct zone *zone, unsigned long phys_start_pfn,
end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
for (i = start_sec; i <= end_sec; i++) {
- err = __add_section(zone, i << PFN_SECTION_SHIFT);
+ err = __add_section(nid, zone, i << PFN_SECTION_SHIFT);
/*
* EEXIST is finally dealt with by ioresource collision