From a16cee10c7ab994546ed98d9abfd4de74050124a Mon Sep 17 00:00:00 2001 From: Wen Congyang Date: Mon, 8 Oct 2012 16:33:58 -0700 Subject: 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 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'drivers/base/memory.c') diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 7dda4f790f0..44e7de6ce69 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: " -- cgit v1.2.3-70-g09d2 From e90bdb7f52f94204c78fb40b0804645defdebd71 Mon Sep 17 00:00:00 2001 From: Wen Congyang Date: Mon, 8 Oct 2012 16:34:01 -0700 Subject: memory-hotplug: update memory block's state and notify userspace remove_memory() will be called when hot removing a memory device. But even if offlining memory, we cannot notice it. So the patch updates the memory block's state and sends notification to userspace. Additionally, the memory device may contain more than one memory block. If the memory block has been offlined, __offline_pages() will fail. So we should try to offline one memory block at a time. Thus remove_memory() also check each memory block's state. So there is no need to check the memory block's state before calling 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 | 31 +++++++++++++++++++++++++++---- include/linux/memory_hotplug.h | 2 ++ mm/memory_hotplug.c | 33 ++++++++++++++++++++++++++++++++- 3 files changed, 61 insertions(+), 5 deletions(-) (limited to 'drivers/base/memory.c') diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 44e7de6ce69..86c88216a50 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -275,13 +275,11 @@ memory_block_action(unsigned long phys_index, unsigned long action) return ret; } -static int memory_block_change_state(struct memory_block *mem, +static int __memory_block_change_state(struct memory_block *mem, unsigned long to_state, unsigned long from_state_req) { int ret = 0; - mutex_lock(&mem->state_mutex); - if (mem->state != from_state_req) { ret = -EINVAL; goto out; @@ -309,10 +307,20 @@ static int memory_block_change_state(struct memory_block *mem, break; } out: - mutex_unlock(&mem->state_mutex); return ret; } +static int memory_block_change_state(struct memory_block *mem, + unsigned long to_state, unsigned long from_state_req) +{ + int ret; + + mutex_lock(&mem->state_mutex); + ret = __memory_block_change_state(mem, to_state, from_state_req); + mutex_unlock(&mem->state_mutex); + + return ret; +} static ssize_t store_mem_state(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) @@ -652,6 +660,21 @@ int unregister_memory_section(struct mem_section *section) return remove_memory_block(0, section, 0); } +/* + * offline one memory block. If the memory block has been offlined, do nothing. + */ +int offline_memory_block(struct memory_block *mem) +{ + int ret = 0; + + mutex_lock(&mem->state_mutex); + if (mem->state != MEM_OFFLINE) + ret = __memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE); + mutex_unlock(&mem->state_mutex); + + return ret; +} + /* * Initialize the sysfs support for memory devices... */ diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index e64fe80eba9..95573ec4ee6 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -10,6 +10,7 @@ struct page; struct zone; struct pglist_data; struct mem_section; +struct memory_block; #ifdef CONFIG_MEMORY_HOTPLUG @@ -234,6 +235,7 @@ 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 offline_memory_block(struct memory_block *mem); 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 dfc0a6134c7..7d0797475a4 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1014,11 +1014,42 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages) int remove_memory(u64 start, u64 size) { + struct memory_block *mem = NULL; + struct mem_section *section; unsigned long start_pfn, end_pfn; + unsigned long pfn, section_nr; + int ret; start_pfn = PFN_DOWN(start); end_pfn = start_pfn + PFN_DOWN(size); - return __offline_pages(start_pfn, end_pfn, 120 * HZ); + + for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + section_nr = pfn_to_section_nr(pfn); + if (!present_section_nr(section_nr)) + continue; + + section = __nr_to_section(section_nr); + /* same memblock? */ + if (mem) + if ((section_nr >= mem->start_section_nr) && + (section_nr <= mem->end_section_nr)) + continue; + + mem = find_memory_block_hinted(section, mem); + if (!mem) + continue; + + ret = offline_memory_block(mem); + if (ret) { + kobject_put(&mem->dev.kobj); + return ret; + } + } + + if (mem) + kobject_put(&mem->dev.kobj); + + return 0; } #else int offline_pages(unsigned long start_pfn, unsigned long nr_pages) -- cgit v1.2.3-70-g09d2