From dee5d0d518defd0337a41f1a504428c9acc87be5 Mon Sep 17 00:00:00 2001 From: Alex Chiang Date: Mon, 14 Dec 2009 17:59:05 -0800 Subject: [PATCH] mm: add numa node symlink for memory section in sysfs Commit c04fc586c (mm: show node to memory section relationship with symlinks in sysfs) created symlinks from nodes to memory sections, e.g. /sys/devices/system/node/node1/memory135 -> ../../memory/memory135 If you're examining the memory section though and are wondering what node it might belong to, you can find it by grovelling around in sysfs, but it's a little cumbersome. Add a reverse symlink for each memory section that points back to the node to which it belongs. Signed-off-by: Alex Chiang Cc: Gary Hade Cc: Badari Pulavarty Cc: Ingo Molnar Acked-by: David Rientjes Cc: Greg KH Cc: Randy Dunlap Cc: David Rientjes Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/ABI/testing/sysfs-devices-memory | 14 +++++++++++++- Documentation/memory-hotplug.txt | 11 +++++++---- drivers/base/node.c | 11 ++++++++++- 3 files changed, 30 insertions(+), 6 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory index 9fe91c02ee40..bf1627b02a03 100644 --- a/Documentation/ABI/testing/sysfs-devices-memory +++ b/Documentation/ABI/testing/sysfs-devices-memory @@ -60,6 +60,19 @@ Description: Users: hotplug memory remove tools https://w3.opensource.ibm.com/projects/powerpc-utils/ + +What: /sys/devices/system/memoryX/nodeY +Date: October 2009 +Contact: Linux Memory Management list +Description: + When CONFIG_NUMA is enabled, a symbolic link that + points to the corresponding NUMA node directory. + + For example, the following symbolic link is created for + memory section 9 on node0: + /sys/devices/system/memory/memory9/node0 -> ../../node/node0 + + What: /sys/devices/system/node/nodeX/memoryY Date: September 2008 Contact: Gary Hade @@ -70,4 +83,3 @@ Description: 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 bbc8a6a36921..57e7e9cc1870 100644 --- a/Documentation/memory-hotplug.txt +++ b/Documentation/memory-hotplug.txt @@ -160,12 +160,15 @@ Under each section, you can see 4 files. 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: +If CONFIG_NUMA is enabled the memoryXXX/ 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 +A backlink will also be created: +/sys/devices/system/memory/memory9/node0 -> ../../node/node0 + -------------------------------- 4. Physical memory hot-add phase -------------------------------- diff --git a/drivers/base/node.c b/drivers/base/node.c index 54e5d8eaf70e..44eed11bbdf3 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -312,6 +312,7 @@ static int get_nid_for_pfn(unsigned long 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) { + int ret; unsigned long pfn, sect_start_pfn, sect_end_pfn; if (!mem_blk) @@ -328,9 +329,15 @@ int register_mem_sect_under_node(struct memory_block *mem_blk, int nid) continue; if (page_nid != nid) continue; - return sysfs_create_link_nowarn(&node_devices[nid].sysdev.kobj, + ret = sysfs_create_link_nowarn(&node_devices[nid].sysdev.kobj, &mem_blk->sysdev.kobj, kobject_name(&mem_blk->sysdev.kobj)); + if (ret) + return ret; + + return sysfs_create_link_nowarn(&mem_blk->sysdev.kobj, + &node_devices[nid].sysdev.kobj, + kobject_name(&node_devices[nid].sysdev.kobj)); } /* mem section does not span the specified node */ return 0; @@ -359,6 +366,8 @@ int unregister_mem_sect_under_nodes(struct memory_block *mem_blk) continue; sysfs_remove_link(&node_devices[nid].sysdev.kobj, kobject_name(&mem_blk->sysdev.kobj)); + sysfs_remove_link(&mem_blk->sysdev.kobj, + kobject_name(&node_devices[nid].sysdev.kobj)); } return 0; } -- 2.20.1