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. Without this patch, we don't know which zone a memory block is in. So we don't know which memory block is adjacent to ZONE_MOVABLE or ZONE_NORMAL. On the other hand, with this patch, we can easy to know newly added memory is added as ZONE_NORMAL (for powerpc, ZONE_DMA, for x86_32, ZONE_HIGHMEM). Updated the related Documentation. Signed-off-by: Zhang Zhen <zhenzhang.zhang@xxxxxxxxxx> --- Documentation/ABI/testing/sysfs-devices-memory | 9 +++++++++ Documentation/memory-hotplug.txt | 4 +++- drivers/base/memory.c | 15 ++++++++++++++- 3 files changed, 26 insertions(+), 2 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory index 7405de2..39d3423 100644 --- a/Documentation/ABI/testing/sysfs-devices-memory +++ b/Documentation/ABI/testing/sysfs-devices-memory @@ -61,6 +61,15 @@ Users: hotplug memory remove tools http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils +What: /sys/devices/system/memory/memoryX/zone_index +Date: July 2014 +Contact: Zhang Zhen <zhenzhang.zhang@xxxxxxxxxx> +Description: + The file /sys/devices/system/memory/memoryX/zone_index + is read-only and is designed to show which zone this memory block is in. +Users: hotplug memory remove tools + http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils + What: /sys/devices/system/memoryX/nodeY Date: October 2009 Contact: Linux Memory Management list <linux-mm@xxxxxxxxx> diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt index 45134dc..07019133 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/zone_index 'phys_index' : read-only and contains memory block id, same as XXX. 'state' : read-write @@ -170,6 +171,8 @@ 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. +'zone_index' : read-only: designed to show which zone this memory block + is in. NOTE: These directories/files appear after physical memory hotplug phase. @@ -408,7 +411,6 @@ 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. diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 89f752d..3434d97 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -373,11 +373,23 @@ static ssize_t show_phys_device(struct device *dev, return sprintf(buf, "%d\n", mem->phys_device); } +static ssize_t show_mem_zone_index(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct memory_block *mem = to_memory_block(dev); + struct page *first_page; + struct zone *zone; + + first_page = pfn_to_page(mem->start_section_nr << PFN_SECTION_SHIFT); + zone = page_zone(first_page); + return sprintf(buf, "%s\n", zone->name); +} + static DEVICE_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL); static DEVICE_ATTR(state, 0644, show_mem_state, store_mem_state); static DEVICE_ATTR(phys_device, 0444, show_phys_device, NULL); static DEVICE_ATTR(removable, 0444, show_mem_removable, NULL); - +static DEVICE_ATTR(zone_index, 0444, show_mem_zone_index, NULL); /* * Block size attribute stuff */ @@ -521,6 +533,7 @@ static struct attribute *memory_memblk_attrs[] = { &dev_attr_state.attr, &dev_attr_phys_device.attr, &dev_attr_removable.attr, + &dev_attr_zone_index.attr, NULL }; -- 1.8.1.2 . -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>