From c04fc586c1a480ba198f03ae7b6cbd7b57380b91 Mon Sep 17 00:00:00 2001 From: Gary Hade Date: Tue, 6 Jan 2009 14:39:14 -0800 Subject: 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 Signed-off-by: Badari Pulavarty Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/ia64/mm/init.c | 2 +- arch/powerpc/mm/mem.c | 2 +- arch/s390/mm/init.c | 2 +- arch/sh/mm/init.c | 3 ++- arch/x86/mm/init_32.c | 2 +- arch/x86/mm/init_64.c | 2 +- 6 files changed, 7 insertions(+), 6 deletions(-) (limited to 'arch') 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; -- cgit v1.2.3-55-g7522