From a16cee10c7ab994546ed98d9abfd4de74050124a Mon Sep 17 00:00:00 2001 From: Wen Congyang Date: Mon, 8 Oct 2012 16:33:58 -0700 Subject: [PATCH] memory-hotplug: preparation to notify memory block's state at memory hot remove remove_memory() is called in two cases: 1. echo offline >/sys/devices/system/memory/memoryXX/state 2. hot remove a memory device In the 1st case, the memory block's state is changed and the notification that memory block's state changed is sent to userland after calling remove_memory(). So user can notice memory block is changed. But in the 2nd case, the memory block's state is not changed and the notification is not also sent to userspcae even if calling remove_memory(). So user cannot notice memory block is changed. For adding the notification at memory hot remove, the patch just prepare as follows: 1st case uses offline_pages() for offlining memory. 2nd case uses remove_memory() for offlining memory and changing memory block's state and notifing the information. The patch does not implement notification to remove_memory(). Signed-off-by: Wen Congyang Signed-off-by: Yasuaki Ishimatsu Cc: David Rientjes Cc: Jiang Liu Cc: Len Brown Cc: Christoph Lameter Cc: Minchan Kim Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/memory.c | 9 +++------ include/linux/memory_hotplug.h | 1 + mm/memory_hotplug.c | 13 +++++++++++-- 3 files changed, 15 insertions(+), 8 deletions(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 7dda4f7..44e7de6 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -248,26 +248,23 @@ static bool pages_correctly_reserved(unsigned long start_pfn, static int memory_block_action(unsigned long phys_index, unsigned long action) { - unsigned long start_pfn, start_paddr; + unsigned long start_pfn; unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block; struct page *first_page; int ret; first_page = pfn_to_page(phys_index << PFN_SECTION_SHIFT); + start_pfn = page_to_pfn(first_page); switch (action) { case MEM_ONLINE: - start_pfn = page_to_pfn(first_page); - if (!pages_correctly_reserved(start_pfn, nr_pages)) return -EBUSY; ret = online_pages(start_pfn, nr_pages); break; case MEM_OFFLINE: - start_paddr = page_to_pfn(first_page) << PAGE_SHIFT; - ret = remove_memory(start_paddr, - nr_pages << PAGE_SHIFT); + ret = offline_pages(start_pfn, nr_pages); break; default: WARN(1, KERN_WARNING "%s(%ld, %ld) unknown action: " diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 910550f..e64fe80 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -233,6 +233,7 @@ static inline int is_mem_section_removable(unsigned long pfn, extern int mem_online_node(int nid); extern int add_memory(int nid, u64 start, u64 size); extern int arch_add_memory(int nid, u64 start, u64 size); +extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages); extern int remove_memory(u64 start, u64 size); extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn, int nr_pages); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index ce690a9..dfc0a61 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -874,7 +874,7 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) return offlined; } -static int __ref offline_pages(unsigned long start_pfn, +static int __ref __offline_pages(unsigned long start_pfn, unsigned long end_pfn, unsigned long timeout) { unsigned long pfn, nr_pages, expire; @@ -1007,15 +1007,24 @@ out: return ret; } +int offline_pages(unsigned long start_pfn, unsigned long nr_pages) +{ + return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ); +} + int remove_memory(u64 start, u64 size) { unsigned long start_pfn, end_pfn; start_pfn = PFN_DOWN(start); end_pfn = start_pfn + PFN_DOWN(size); - return offline_pages(start_pfn, end_pfn, 120 * HZ); + return __offline_pages(start_pfn, end_pfn, 120 * HZ); } #else +int offline_pages(unsigned long start_pfn, unsigned long nr_pages) +{ + return -EINVAL; +} int remove_memory(u64 start, u64 size) { return -EINVAL; -- 2.7.4