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 --- drivers/base/memory.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) (limited to 'drivers/base') 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 }; -- cgit v1.2.3-59-g8ed1b