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 added to which zone, and we don't need to know the above two limits. Updated the related Documentation. Signed-off-by: Zhang Zhen <zhenzhang.zhang@xxxxxxxxxx> --- Documentation/ABI/testing/sysfs-devices-memory | 10 +++++ Documentation/memory-hotplug.txt | 4 +- drivers/base/memory.c | 62 +++++++++++++++++++++++++- include/linux/memory_hotplug.h | 1 + mm/memory_hotplug.c | 4 +- 5 files changed, 77 insertions(+), 4 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory index 7405de2..0e58924 100644 --- a/Documentation/ABI/testing/sysfs-devices-memory +++ b/Documentation/ABI/testing/sysfs-devices-memory @@ -61,6 +61,16 @@ Users: hotplug memory remove tools http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils +What: /sys/devices/system/memory/memoryX/zone_to_online +Date: July 2014 +Contact: Zhang Zhen <zhenzhang.zhang@xxxxxxxxxx> +Description: + The file /sys/devices/system/memory/memoryX/zone_to_online + is read-only and is designed to show which zone this memory block can + be onlined to. +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..09e3d37 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_to_online '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_to_online' : read-only: designed to show which zone this memory block + can be onlined to. 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 a2e13e2..044353c 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -373,11 +373,70 @@ static ssize_t show_phys_device(struct device *dev, return sprintf(buf, "%d\n", mem->phys_device); } +static ssize_t show_zone_to_online(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, *zone_prev, *zone_next; + + first_page = pfn_to_page(mem->start_section_nr << PFN_SECTION_SHIFT); + start_pfn = page_to_pfn(first_page); + end_pfn = start_pfn + nr_pages; + + /*The block contains more than one zone can not be offlined.*/ + if (!test_pages_in_a_zone(start_pfn, end_pfn)) + return sprintf(buf, "NULL\n"); + + zone = page_zone(first_page); + + /*The mem block is the last block of memory.*/ + if (!pfn_valid(end_pfn + 1)) { +#ifdef CONFIG_HIGHMEM + if (zone_idx(zone) == ZONE_HIGHMEM) + return sprintf(buf, "%s %s\n", zone->name, (zone + 1)->name); +#else + if (zone_idx(zone) == ZONE_NORMAL) + return sprintf(buf, "%s %s\n", zone->name, (zone + 1)->name); +#endif + if (zone_idx(zone) == ZONE_MOVABLE) { + if (pfn_valid(start_pfn - nr_pages)) { + zone_prev = page_zone(first_page - nr_pages); + if (zone_idx(zone_prev) != ZONE_MOVABLE) + return sprintf(buf, "%s %s\n", zone->name, (zone - 1)->name); + } else + return sprintf(buf, "%s %s\n", zone->name, (zone - 1)->name); + } + return sprintf(buf, "%s\n", zone->name); + + } + + zone_next = page_zone(first_page + nr_pages + 1); +#ifdef CONFIG_HIGHMEM + if (zone_idx(zone) == ZONE_HIGHMEM && zone_idx(zone_next) == ZONE_MOVABLE) + return sprintf(buf, "%s %s\n", zone->name, zone_next->name); +#else + if (zone_idx(zone) == ZONE_NORMAL && zone_idx(zone_next) == ZONE_MOVABLE) + return sprintf(buf, "%s %s\n", zone->name, zone_next->name); +#endif + if (zone_idx(zone) == ZONE_MOVABLE) { + if (pfn_valid(start_pfn - nr_pages)) { + zone_prev = page_zone(first_page - nr_pages); + if (zone_idx(zone_prev) != ZONE_MOVABLE) + return sprintf(buf, "%s %s\n", zone->name, (zone - 1)->name); + } else + return sprintf(buf, "%s %s\n", zone->name, (zone - 1)->name); + } + 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_to_online, 0444, show_zone_to_online, NULL); /* * Block size attribute stuff */ @@ -523,6 +582,7 @@ static struct attribute *memory_memblk_attrs[] = { &dev_attr_state.attr, &dev_attr_phys_device.attr, &dev_attr_removable.attr, + &dev_attr_zone_to_online.attr, NULL }; diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index d9524c4..8f1a419 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 2ff8c23..785b7e6 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; @@ -1638,7 +1638,7 @@ static void node_states_clear_node(int node, struct memory_notify *arg) node_clear_state(node, N_MEMORY); } -static int __ref __offline_pages(unsigned long start_pfn, +int __ref __offline_pages(unsigned long start_pfn, unsigned long end_pfn, unsigned long timeout) { unsigned long pfn, nr_pages, expire; -- 1.8.1.2 . -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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