(2014/08/19 16:35), Zhang Zhen wrote:
On 2014/8/18 14:11, Yasuaki Ishimatsu wrote:(2014/08/13 13:10), Zhang Zhen wrote: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. Change v1 -> v2: - optimize the implementation following Dave Hansen's suggestion Signed-off-by: Zhang Zhen <zhenzhang.zhang@xxxxxxxxxx> --- Documentation/ABI/testing/sysfs-devices-memory | 8 ++++ Documentation/memory-hotplug.txt | 4 +- drivers/base/memory.c | 62 ++++++++++++++++++++++++++ include/linux/memory_hotplug.h | 1 + mm/memory_hotplug.c | 2 +- 5 files changed, 75 insertions(+), 2 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory index 7405de2..2b2a1d7 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/zones_online_to +Date: July 2014 +Contact: Zhang Zhen <zhenzhang.zhang@xxxxxxxxxx> +Description: + The file /sys/devices/system/memory/memoryX/zones_online_to + 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 <linux-mm@xxxxxxxxx> diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt index 45134dc..5b34e33 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/zones_online_to '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. +'zones_online_to' : 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..b5d693f 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -373,10 +373,71 @@ static ssize_t show_phys_device(struct device *dev, return sprintf(buf, "%d\n", mem->phys_device); } +static int __zones_online_to(unsigned long end_pfn, + struct page *first_page, unsigned long nr_pages) +{ + struct zone *zone_next; ++ /*The mem block is the last block of memory.*/ + if (!pfn_valid(end_pfn + 1)) + return 1;The check is not enough if memory has hole as follows: PFN 0x00 0xd0 0xe0 0xf0 +-------------+-------------+-------------+ zone type | Normal | hole | Normal | +-------------+-------------+-------------+ In this case, 0xd1 is invalid pfn. But __zones_online_to should return 0 since 0xe0-0xf0 is Normal zone. Thanks, Yasuaki IshimatsuYou are right, it is not enough.
Here we should make a check as follows. if ((end_pfn + 1) > zone_end_pfn(page_zone(first_page))) return 1; I will send a patch to fix it.
It's looks good to me. Thanks, Yasuaki Ishimatsu
Thanks !+ zone_next = page_zone(first_page + nr_pages); + if (zone_idx(zone_next) == ZONE_MOVABLE) + return 1; + return 0; +} + +static ssize_t show_zones_online_to(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; + + 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); + +#ifdef CONFIG_HIGHMEM + if (zone_idx(zone) == ZONE_HIGHMEM) { + if (__zones_online_to(end_pfn, first_page, nr_pages)) + return sprintf(buf, "%s %s\n", + zone->name, (zone + 1)->name); + } +#else + if (zone_idx(zone) == ZONE_NORMAL) { + if (__zones_online_to(end_pfn, first_page, nr_pages)) + 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)) + return sprintf(buf, "%s %s\n", + zone->name, (zone - 1)->name); + 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); + } + + 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(zones_online_to, 0444, show_zones_online_to, NULL); /* * Block size attribute stuff @@ -523,6 +584,7 @@ static struct attribute *memory_memblk_attrs[] = { &dev_attr_state.attr, &dev_attr_phys_device.attr, &dev_attr_removable.attr, + &dev_attr_zones_online_to.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..29d8693 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;-- 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> .
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