forked from Minki/linux
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>
This commit is contained in:
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@ -6,7 +6,6 @@ Description:
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internal state of the kernel memory blocks. Files could be
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added or removed dynamically to represent hot-add/remove
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operations.
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Users: hotplug memory add/remove tools
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https://w3.opensource.ibm.com/projects/powerpc-utils/
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@ -19,6 +18,56 @@ Description:
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This is useful for a user-level agent to determine
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identify removable sections of the memory before attempting
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potentially expensive hot-remove memory operation
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Users: hotplug memory remove tools
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https://w3.opensource.ibm.com/projects/powerpc-utils/
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What: /sys/devices/system/memory/memoryX/phys_device
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Date: September 2008
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Contact: Badari Pulavarty <pbadari@us.ibm.com>
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Description:
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The file /sys/devices/system/memory/memoryX/phys_device
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is read-only and is designed to show the name of physical
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memory device. Implementation is currently incomplete.
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What: /sys/devices/system/memory/memoryX/phys_index
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Date: September 2008
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Contact: Badari Pulavarty <pbadari@us.ibm.com>
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Description:
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The file /sys/devices/system/memory/memoryX/phys_index
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is read-only and contains the section ID in hexadecimal
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which is equivalent to decimal X contained in the
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memory section directory name.
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What: /sys/devices/system/memory/memoryX/state
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Date: September 2008
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Contact: Badari Pulavarty <pbadari@us.ibm.com>
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Description:
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The file /sys/devices/system/memory/memoryX/state
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is read-write. When read, it's contents show the
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online/offline state of the memory section. When written,
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root can toggle the the online/offline state of a removable
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memory section (see removable file description above)
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using the following commands.
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# echo online > /sys/devices/system/memory/memoryX/state
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# echo offline > /sys/devices/system/memory/memoryX/state
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For example, if /sys/devices/system/memory/memory22/removable
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contains a value of 1 and
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/sys/devices/system/memory/memory22/state contains the
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string "online" the following command can be executed by
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by root to offline that section.
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# echo offline > /sys/devices/system/memory/memory22/state
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Users: hotplug memory remove tools
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https://w3.opensource.ibm.com/projects/powerpc-utils/
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What: /sys/devices/system/node/nodeX/memoryY
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Date: September 2008
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Contact: Gary Hade <garyhade@us.ibm.com>
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Description:
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When CONFIG_NUMA is enabled
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/sys/devices/system/node/nodeX/memoryY is a symbolic link that
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points to the corresponding /sys/devices/system/memory/memoryY
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memory section directory. For example, the following symbolic
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link is created for memory section 9 on node0.
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/sys/devices/system/node/node0/memory9 -> ../../memory/memory9
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@ -124,7 +124,7 @@ config options.
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This option can be kernel module too.
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--------------------------------
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3 sysfs files for memory hotplug
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4 sysfs files for memory hotplug
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--------------------------------
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All sections have their device information under /sys/devices/system/memory as
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@ -138,11 +138,12 @@ For example, assume 1GiB section size. A device for a memory starting at
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(0x100000000 / 1Gib = 4)
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This device covers address range [0x100000000 ... 0x140000000)
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Under each section, you can see 3 files.
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Under each section, you can see 4 files.
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/sys/devices/system/memory/memoryXXX/phys_index
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/sys/devices/system/memory/memoryXXX/phys_device
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/sys/devices/system/memory/memoryXXX/state
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/sys/devices/system/memory/memoryXXX/removable
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'phys_index' : read-only and contains section id, same as XXX.
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'state' : read-write
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@ -150,10 +151,20 @@ Under each section, you can see 3 files.
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at write: user can specify "online", "offline" command
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'phys_device': read-only: designed to show the name of physical memory device.
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This is not well implemented now.
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'removable' : read-only: contains an integer value indicating
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whether the memory section is removable or not
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removable. A value of 1 indicates that the memory
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section is removable and a value of 0 indicates that
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it is not removable.
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NOTE:
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These directories/files appear after physical memory hotplug phase.
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If CONFIG_NUMA is enabled the
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/sys/devices/system/memory/memoryXXX memory section
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directories can also be accessed via symbolic links located in
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the /sys/devices/system/node/node* directories. For example:
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/sys/devices/system/node/node0/memory9 -> ../../memory/memory9
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--------------------------------
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4. Physical memory hot-add phase
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@ -365,7 +376,6 @@ node if necessary.
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- allowing memory hot-add to ZONE_MOVABLE. maybe we need some switch like
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sysctl or new control file.
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- showing memory section and physical device relationship.
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- showing memory section and node relationship (maybe good for NUMA)
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- showing memory section is under ZONE_MOVABLE or not
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- test and make it better memory offlining.
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- support HugeTLB page migration and offlining.
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@ -692,7 +692,7 @@ int arch_add_memory(int nid, u64 start, u64 size)
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pgdat = NODE_DATA(nid);
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zone = pgdat->node_zones + ZONE_NORMAL;
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ret = __add_pages(zone, start_pfn, nr_pages);
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ret = __add_pages(nid, zone, start_pfn, nr_pages);
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if (ret)
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printk("%s: Problem encountered in __add_pages() as ret=%d\n",
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@ -132,7 +132,7 @@ int arch_add_memory(int nid, u64 start, u64 size)
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/* this should work for most non-highmem platforms */
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zone = pgdata->node_zones;
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return __add_pages(zone, start_pfn, nr_pages);
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return __add_pages(nid, zone, start_pfn, nr_pages);
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}
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#endif /* CONFIG_MEMORY_HOTPLUG */
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@ -183,7 +183,7 @@ int arch_add_memory(int nid, u64 start, u64 size)
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rc = vmem_add_mapping(start, size);
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if (rc)
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return rc;
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rc = __add_pages(zone, PFN_DOWN(start), PFN_DOWN(size));
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rc = __add_pages(nid, zone, PFN_DOWN(start), PFN_DOWN(size));
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if (rc)
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vmem_remove_mapping(start, size);
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return rc;
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@ -311,7 +311,8 @@ int arch_add_memory(int nid, u64 start, u64 size)
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pgdat = NODE_DATA(nid);
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/* We only have ZONE_NORMAL, so this is easy.. */
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ret = __add_pages(pgdat->node_zones + ZONE_NORMAL, start_pfn, nr_pages);
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ret = __add_pages(nid, pgdat->node_zones + ZONE_NORMAL,
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start_pfn, nr_pages);
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if (unlikely(ret))
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printk("%s: Failed, __add_pages() == %d\n", __func__, ret);
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@ -1079,7 +1079,7 @@ int arch_add_memory(int nid, u64 start, u64 size)
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unsigned long start_pfn = start >> PAGE_SHIFT;
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unsigned long nr_pages = size >> PAGE_SHIFT;
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return __add_pages(zone, start_pfn, nr_pages);
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return __add_pages(nid, zone, start_pfn, nr_pages);
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}
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#endif
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@ -857,7 +857,7 @@ int arch_add_memory(int nid, u64 start, u64 size)
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if (last_mapped_pfn > max_pfn_mapped)
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max_pfn_mapped = last_mapped_pfn;
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ret = __add_pages(zone, start_pfn, nr_pages);
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ret = __add_pages(nid, zone, start_pfn, nr_pages);
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WARN_ON_ONCE(ret);
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return ret;
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@ -347,8 +347,9 @@ static inline int memory_probe_init(void)
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* section belongs to...
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*/
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static int add_memory_block(unsigned long node_id, struct mem_section *section,
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unsigned long state, int phys_device)
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static int add_memory_block(int nid, struct mem_section *section,
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unsigned long state, int phys_device,
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enum mem_add_context context)
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{
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struct memory_block *mem = kzalloc(sizeof(*mem), GFP_KERNEL);
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int ret = 0;
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@ -370,6 +371,10 @@ static int add_memory_block(unsigned long node_id, struct mem_section *section,
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ret = mem_create_simple_file(mem, phys_device);
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if (!ret)
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ret = mem_create_simple_file(mem, removable);
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if (!ret) {
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if (context == HOTPLUG)
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ret = register_mem_sect_under_node(mem, nid);
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}
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return ret;
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}
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@ -382,7 +387,7 @@ static int add_memory_block(unsigned long node_id, struct mem_section *section,
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*
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* This could be made generic for all sysdev classes.
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*/
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static struct memory_block *find_memory_block(struct mem_section *section)
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struct memory_block *find_memory_block(struct mem_section *section)
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{
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struct kobject *kobj;
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struct sys_device *sysdev;
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@ -411,6 +416,7 @@ int remove_memory_block(unsigned long node_id, struct mem_section *section,
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struct memory_block *mem;
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mem = find_memory_block(section);
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unregister_mem_sect_under_nodes(mem);
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mem_remove_simple_file(mem, phys_index);
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mem_remove_simple_file(mem, state);
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mem_remove_simple_file(mem, phys_device);
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@ -424,9 +430,9 @@ int remove_memory_block(unsigned long node_id, struct mem_section *section,
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* need an interface for the VM to add new memory regions,
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* but without onlining it.
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*/
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int register_new_memory(struct mem_section *section)
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int register_new_memory(int nid, struct mem_section *section)
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{
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return add_memory_block(0, section, MEM_OFFLINE, 0);
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return add_memory_block(nid, section, MEM_OFFLINE, 0, HOTPLUG);
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}
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int unregister_memory_section(struct mem_section *section)
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@ -458,7 +464,8 @@ int __init memory_dev_init(void)
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for (i = 0; i < NR_MEM_SECTIONS; i++) {
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if (!present_section_nr(i))
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continue;
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err = add_memory_block(0, __nr_to_section(i), MEM_ONLINE, 0);
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err = add_memory_block(0, __nr_to_section(i), MEM_ONLINE,
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0, BOOT);
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if (!ret)
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ret = err;
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}
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@ -6,6 +6,7 @@
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/memory.h>
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#include <linux/node.h>
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#include <linux/hugetlb.h>
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#include <linux/cpumask.h>
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@ -248,6 +249,105 @@ int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
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return 0;
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}
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#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
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#define page_initialized(page) (page->lru.next)
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static int get_nid_for_pfn(unsigned long pfn)
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{
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struct page *page;
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if (!pfn_valid_within(pfn))
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return -1;
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page = pfn_to_page(pfn);
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if (!page_initialized(page))
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return -1;
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return pfn_to_nid(pfn);
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}
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/* register memory section under specified node if it spans that node */
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int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
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{
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unsigned long pfn, sect_start_pfn, sect_end_pfn;
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if (!mem_blk)
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return -EFAULT;
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if (!node_online(nid))
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return 0;
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sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
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sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
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for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
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int page_nid;
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page_nid = get_nid_for_pfn(pfn);
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if (page_nid < 0)
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continue;
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if (page_nid != nid)
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continue;
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return sysfs_create_link_nowarn(&node_devices[nid].sysdev.kobj,
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&mem_blk->sysdev.kobj,
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kobject_name(&mem_blk->sysdev.kobj));
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}
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/* mem section does not span the specified node */
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return 0;
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}
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/* unregister memory section under all nodes that it spans */
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int unregister_mem_sect_under_nodes(struct memory_block *mem_blk)
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{
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nodemask_t unlinked_nodes;
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unsigned long pfn, sect_start_pfn, sect_end_pfn;
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if (!mem_blk)
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return -EFAULT;
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nodes_clear(unlinked_nodes);
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sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
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sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
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for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
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unsigned int nid;
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nid = get_nid_for_pfn(pfn);
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if (nid < 0)
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continue;
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if (!node_online(nid))
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continue;
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if (node_test_and_set(nid, unlinked_nodes))
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continue;
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sysfs_remove_link(&node_devices[nid].sysdev.kobj,
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kobject_name(&mem_blk->sysdev.kobj));
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}
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return 0;
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}
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static int link_mem_sections(int nid)
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{
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unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
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unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
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unsigned long pfn;
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int err = 0;
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for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
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unsigned long section_nr = pfn_to_section_nr(pfn);
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struct mem_section *mem_sect;
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struct memory_block *mem_blk;
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int ret;
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if (!present_section_nr(section_nr))
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continue;
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mem_sect = __nr_to_section(section_nr);
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mem_blk = find_memory_block(mem_sect);
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ret = register_mem_sect_under_node(mem_blk, nid);
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if (!err)
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err = ret;
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/* discard ref obtained in find_memory_block() */
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kobject_put(&mem_blk->sysdev.kobj);
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}
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return err;
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}
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#else
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static int link_mem_sections(int nid) { return 0; }
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#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
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int register_one_node(int nid)
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{
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int error = 0;
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@ -267,6 +367,9 @@ int register_one_node(int nid)
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if (cpu_to_node(cpu) == nid)
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register_cpu_under_node(cpu, nid);
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}
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/* link memory sections under this node */
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error = link_mem_sections(nid);
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}
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return error;
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@ -79,14 +79,14 @@ static inline int memory_notify(unsigned long val, void *v)
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#else
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extern int register_memory_notifier(struct notifier_block *nb);
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extern void unregister_memory_notifier(struct notifier_block *nb);
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extern int register_new_memory(struct mem_section *);
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extern int register_new_memory(int, struct mem_section *);
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extern int unregister_memory_section(struct mem_section *);
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extern int memory_dev_init(void);
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extern int remove_memory_block(unsigned long, struct mem_section *, int);
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extern int memory_notify(unsigned long val, void *v);
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extern struct memory_block *find_memory_block(struct mem_section *);
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#define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT)
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enum mem_add_context { BOOT, HOTPLUG };
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#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
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#ifdef CONFIG_MEMORY_HOTPLUG
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@ -72,7 +72,7 @@ extern void __offline_isolated_pages(unsigned long, unsigned long);
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extern int offline_pages(unsigned long, unsigned long, unsigned long);
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/* reasonably generic interface to expand the physical pages in a zone */
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extern int __add_pages(struct zone *zone, unsigned long start_pfn,
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extern int __add_pages(int nid, struct zone *zone, unsigned long start_pfn,
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unsigned long nr_pages);
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extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
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unsigned long nr_pages);
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@ -26,6 +26,7 @@ struct node {
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struct sys_device sysdev;
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};
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struct memory_block;
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extern struct node node_devices[];
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extern int register_node(struct node *, int, struct node *);
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@ -35,6 +36,9 @@ extern int register_one_node(int nid);
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extern void unregister_one_node(int nid);
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||||
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)
|
||||
|
@ -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
|
||||
|
Loading…
Reference in New Issue
Block a user