From ed2f240094f900833ac06f533ab8bbcf0a1e8199 Mon Sep 17 00:00:00 2001 From: Zhang Zhen Date: Thu, 9 Oct 2014 15:26:31 -0700 Subject: [PATCH] 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 --- .../ABI/testing/sysfs-devices-memory | 8 ++++ Documentation/memory-hotplug.txt | 11 ++++- drivers/base/memory.c | 42 +++++++++++++++++++ include/linux/memory_hotplug.h | 1 + mm/memory_hotplug.c | 2 +- 5 files changed, 62 insertions(+), 2 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory index 7405de26ee60..deef3b5723cf 100644 --- a/Documentation/ABI/testing/sysfs-devices-memory +++ b/Documentation/ABI/testing/sysfs-devices-memory @@ -61,6 +61,14 @@ Users: hotplug memory remove tools http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils +What: /sys/devices/system/memory/memoryX/valid_zones +Date: July 2014 +Contact: Zhang Zhen +Description: + The file /sys/devices/system/memory/memoryX/valid_zones is + read-only and is designed to show which zone this memory + block can be onlined to. + What: /sys/devices/system/memoryX/nodeY Date: October 2009 Contact: Linux Memory Management list 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. diff --git a/drivers/base/memory.c b/drivers/base/memory.c index a2e13e250bba..7c5d87191b28 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -373,6 +373,45 @@ static ssize_t show_phys_device(struct device *dev, return sprintf(buf, "%d\n", mem->phys_device); } +#ifdef CONFIG_MEMORY_HOTREMOVE +static ssize_t show_valid_zones(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct memory_block *mem = to_memory_block(dev); + unsigned long start_pfn, end_pfn; + unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block; + struct page *first_page; + struct zone *zone; + + start_pfn = section_nr_to_pfn(mem->start_section_nr); + end_pfn = start_pfn + nr_pages; + first_page = pfn_to_page(start_pfn); + + /* The block contains more than one zone can not be offlined. */ + if (!test_pages_in_a_zone(start_pfn, end_pfn)) + return sprintf(buf, "none\n"); + + zone = page_zone(first_page); + + if (zone_idx(zone) == ZONE_MOVABLE - 1) { + /*The mem block is the last memoryblock of this zone.*/ + if (end_pfn == zone_end_pfn(zone)) + return sprintf(buf, "%s %s\n", + zone->name, (zone + 1)->name); + } + + if (zone_idx(zone) == ZONE_MOVABLE) { + /*The mem block is the first memoryblock of ZONE_MOVABLE.*/ + if (start_pfn == zone->zone_start_pfn) + return sprintf(buf, "%s %s\n", + zone->name, (zone - 1)->name); + } + + return sprintf(buf, "%s\n", zone->name); +} +static DEVICE_ATTR(valid_zones, 0444, show_valid_zones, NULL); +#endif + 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); @@ -523,6 +562,9 @@ static struct attribute *memory_memblk_attrs[] = { &dev_attr_state.attr, &dev_attr_phys_device.attr, &dev_attr_removable.attr, +#ifdef CONFIG_MEMORY_HOTREMOVE + &dev_attr_valid_zones.attr, +#endif NULL }; diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index d9524c49d767..8f1a41951df9 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -84,6 +84,7 @@ extern int zone_grow_waitqueues(struct zone *zone, unsigned long nr_pages); extern int add_one_highpage(struct page *page, int pfn, int bad_ppro); /* VM interface that may be used by firmware interface */ extern int online_pages(unsigned long, unsigned long, int); +extern int test_pages_in_a_zone(unsigned long, unsigned long); extern void __offline_isolated_pages(unsigned long, unsigned long); typedef void (*online_page_callback_t)(struct page *page); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 2ff8c2325e96..29d8693d0c61 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1307,7 +1307,7 @@ int is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages) /* * Confirm all pages in a range [start, end) is belongs to the same zone. */ -static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn) +int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn) { unsigned long pfn; struct zone *zone = NULL; -- 2.20.1