From ed2f240094f900833ac06f533ab8bbcf0a1e8199 Mon Sep 17 00:00:00 2001 From: Zhang Zhen Date: Thu, 9 Oct 2014 15:26:31 -0700 Subject: memory-hotplug: add sysfs valid_zones attribute Currently memory-hotplug has two limits: 1. If the memory block is in ZONE_NORMAL, you can change it to ZONE_MOVABLE, but this memory block must be adjacent to ZONE_MOVABLE. 2. If the memory block is in ZONE_MOVABLE, you can change it to ZONE_NORMAL, but this memory block must be adjacent to ZONE_NORMAL. With this patch, we can easy to know a memory block can be onlined to which zone, and don't need to know the above two limits. Updated the related Documentation. [akpm@linux-foundation.org: use conventional comment layout] [akpm@linux-foundation.org: fix build with CONFIG_MEMORY_HOTREMOVE=n] [akpm@linux-foundation.org: remove unused local zone_prev] Signed-off-by: Zhang Zhen Cc: Dave Hansen Cc: David Rientjes Cc: Toshi Kani Cc: Yasuaki Ishimatsu Cc: Naoya Horiguchi Cc: Wang Nan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/memory-hotplug.txt | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'Documentation/memory-hotplug.txt') diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt index 45134dc23854..ea03abfc97e9 100644 --- a/Documentation/memory-hotplug.txt +++ b/Documentation/memory-hotplug.txt @@ -155,6 +155,7 @@ Under each memory block, you can see 4 files: /sys/devices/system/memory/memoryXXX/phys_device /sys/devices/system/memory/memoryXXX/state /sys/devices/system/memory/memoryXXX/removable +/sys/devices/system/memory/memoryXXX/valid_zones 'phys_index' : read-only and contains memory block id, same as XXX. 'state' : read-write @@ -170,6 +171,15 @@ Under each memory block, you can see 4 files: block is removable and a value of 0 indicates that it is not removable. A memory block is removable only if every section in the block is removable. +'valid_zones' : read-only: designed to show which zones this memory block + can be onlined to. + The first column shows it's default zone. + "memory6/valid_zones: Normal Movable" shows this memoryblock + can be onlined to ZONE_NORMAL by default and to ZONE_MOVABLE + by online_movable. + "memory7/valid_zones: Movable Normal" shows this memoryblock + can be onlined to ZONE_MOVABLE by default and to ZONE_NORMAL + by online_kernel. NOTE: These directories/files appear after physical memory hotplug phase. @@ -408,7 +418,6 @@ node if necessary. - allowing memory hot-add to ZONE_MOVABLE. maybe we need some switch like sysctl or new control file. - showing memory block and physical device relationship. - - showing memory block is under ZONE_MOVABLE or not - test and make it better memory offlining. - support HugeTLB page migration and offlining. - memmap removing at memory offline. -- cgit v1.2.3-58-ga151