From 6677e3eaf4d78abd7b09133414c05dc3ec353e7f Mon Sep 17 00:00:00 2001 From: Yasuaki Ishimatsu Date: Fri, 22 Feb 2013 16:32:52 -0800 Subject: memory-hotplug: check whether all memory blocks are offlined or not when removing memory We remove the memory like this: 1. lock memory hotplug 2. offline a memory block 3. unlock memory hotplug 4. repeat 1-3 to offline all memory blocks 5. lock memory hotplug 6. remove memory(TODO) 7. unlock memory hotplug All memory blocks must be offlined before removing memory. But we don't hold the lock in the whole operation. So we should check whether all memory blocks are offlined before step6. Otherwise, kernel maybe panicked. Offlining a memory block and removing a memory device can be two different operations. Users can just offline some memory blocks without removing the memory device. For this purpose, the kernel has held lock_memory_hotplug() in __offline_pages(). To reuse the code for memory hot-remove, we repeat step 1-3 to offline all the memory blocks, repeatedly lock and unlock memory hotplug, but not hold the memory hotplug lock in the whole operation. Signed-off-by: Wen Congyang Signed-off-by: Yasuaki Ishimatsu Signed-off-by: Tang Chen Acked-by: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Jiang Liu Cc: Jianguo Wu Cc: Kamezawa Hiroyuki Cc: Lai Jiangshan Cc: Wu Jianguo Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memory_hotplug.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/memory_hotplug.h') diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 4a45c4e50025..8dd0950a6a7a 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -247,6 +247,7 @@ 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 bool is_memblock_offlined(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); -- cgit v1.2.3 From 24d335ca3606b610ec69c66a1e42760c96d89470 Mon Sep 17 00:00:00 2001 From: Wen Congyang Date: Fri, 22 Feb 2013 16:32:58 -0800 Subject: memory-hotplug: introduce new arch_remove_memory() for removing page table For removing memory, we need to remove page tables. But it depends on architecture. So the patch introduce arch_remove_memory() for removing page table. Now it only calls __remove_pages(). Note: __remove_pages() for some archtecuture is not implemented (I don't know how to implement it for s390). Signed-off-by: Wen Congyang Signed-off-by: Tang Chen Acked-by: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Jiang Liu Cc: Jianguo Wu Cc: Kamezawa Hiroyuki Cc: Lai Jiangshan Cc: Wu Jianguo Cc: Yasuaki Ishimatsu Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memory_hotplug.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/memory_hotplug.h') diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 8dd0950a6a7a..31a563bbd936 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -96,6 +96,7 @@ extern void __online_page_free(struct page *page); #ifdef CONFIG_MEMORY_HOTREMOVE extern bool is_pageblock_removable_nolock(struct page *page); +extern int arch_remove_memory(u64 start, u64 size); #endif /* CONFIG_MEMORY_HOTREMOVE */ /* reasonably generic interface to expand the physical pages in a zone */ -- cgit v1.2.3 From 46723bfa540f0a1e494476a1734d03626a0bd1e0 Mon Sep 17 00:00:00 2001 From: Yasuaki Ishimatsu Date: Fri, 22 Feb 2013 16:33:00 -0800 Subject: memory-hotplug: implement register_page_bootmem_info_section of sparse-vmemmap For removing memmap region of sparse-vmemmap which is allocated bootmem, memmap region of sparse-vmemmap needs to be registered by get_page_bootmem(). So the patch searches pages of virtual mapping and registers the pages by get_page_bootmem(). NOTE: register_page_bootmem_memmap() is not implemented for ia64, ppc, s390, and sparc. So introduce CONFIG_HAVE_BOOTMEM_INFO_NODE and revert register_page_bootmem_info_node() when platform doesn't support it. It's implemented by adding a new Kconfig option named CONFIG_HAVE_BOOTMEM_INFO_NODE, which will be automatically selected by memory-hotplug feature fully supported archs(currently only on x86_64). Since we have 2 config options called MEMORY_HOTPLUG and MEMORY_HOTREMOVE used for memory hot-add and hot-remove separately, and codes in function register_page_bootmem_info_node() are only used for collecting infomation for hot-remove, so reside it under MEMORY_HOTREMOVE. Besides page_isolation.c selected by MEMORY_ISOLATION under MEMORY_HOTPLUG is also such case, move it too. [mhocko@suse.cz: put register_page_bootmem_memmap inside CONFIG_MEMORY_HOTPLUG_SPARSE] [linfeng@cn.fujitsu.com: introduce CONFIG_HAVE_BOOTMEM_INFO_NODE and revert register_page_bootmem_info_node()] [mhocko@suse.cz: remove the arch specific functions without any implementation] [linfeng@cn.fujitsu.com: mm/Kconfig: move auto selects from MEMORY_HOTPLUG to MEMORY_HOTREMOVE as needed] [rientjes@google.com: fix defined but not used warning] Signed-off-by: Wen Congyang Signed-off-by: Yasuaki Ishimatsu Signed-off-by: Tang Chen Reviewed-by: Wu Jianguo Cc: KOSAKI Motohiro Cc: Jiang Liu Cc: Jianguo Wu Cc: Kamezawa Hiroyuki Cc: Lai Jiangshan Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Signed-off-by: Michal Hocko Signed-off-by: Lin Feng Signed-off-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memory_hotplug.h | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'include/linux/memory_hotplug.h') diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 31a563bbd936..4d523fe75ba1 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -174,17 +174,16 @@ static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat) #endif /* CONFIG_NUMA */ #endif /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */ -#ifdef CONFIG_SPARSEMEM_VMEMMAP +#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE +extern void register_page_bootmem_info_node(struct pglist_data *pgdat); +#else static inline void register_page_bootmem_info_node(struct pglist_data *pgdat) { } -static inline void put_page_bootmem(struct page *page) -{ -} -#else -extern void register_page_bootmem_info_node(struct pglist_data *pgdat); -extern void put_page_bootmem(struct page *page); #endif +extern void put_page_bootmem(struct page *page); +extern void get_page_bootmem(unsigned long ingo, struct page *page, + unsigned long type); /* * Lock for memory hotplug guarantees 1) all callbacks for memory hotplug -- cgit v1.2.3 From 60a5a19e7419ba0bc22ed01b3285e8940b42944c Mon Sep 17 00:00:00 2001 From: Tang Chen Date: Fri, 22 Feb 2013 16:33:14 -0800 Subject: memory-hotplug: remove sysfs file of node Introduce a new function try_offline_node() to remove sysfs file of node when all memory sections of this node are removed. If some memory sections of this node are not removed, this function does nothing. Signed-off-by: Wen Congyang Signed-off-by: Tang Chen Cc: KOSAKI Motohiro Cc: Jiang Liu Cc: Jianguo Wu Cc: Kamezawa Hiroyuki Cc: Lai Jiangshan Cc: Wu Jianguo Cc: Yasuaki Ishimatsu Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memory_hotplug.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/memory_hotplug.h') diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 4d523fe75ba1..69903ccf549e 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -248,7 +248,7 @@ 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 bool is_memblock_offlined(struct memory_block *mem); -extern int remove_memory(u64 start, u64 size); +extern int remove_memory(int nid, u64 start, u64 size); extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn, int nr_pages); extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms); -- cgit v1.2.3 From 90b30cdc1d87450e2ae89c8f8a29102dc2c1992e Mon Sep 17 00:00:00 2001 From: Wen Congyang Date: Fri, 22 Feb 2013 16:33:27 -0800 Subject: memory-hotplug: export the function try_offline_node() try_offline_node() will be needed in the tristate drivers/acpi/processor_driver.c. The node will be offlined when all memory/cpu on the node have been hotremoved. So we need the function try_offline_node() in cpu-hotplug path. If the memory-hotplug is disabled, and cpu-hotplug is enabled 1. no memory no the node we don't online the node, and cpu's node is the nearest node. 2. the node contains some memory the node has been onlined, and cpu's node is still needed to migrate the sleep task on the cpu to the same node. So we do nothing in try_offline_node() in this case. [rientjes@google.com: export the function try_offline_node() fix] Signed-off-by: Wen Congyang Signed-off-by: Tang Chen Cc: Yasuaki Ishimatsu Cc: David Rientjes Cc: Jiang Liu Cc: Minchan Kim Cc: KOSAKI Motohiro Cc: Mel Gorman Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Peter Zijlstra Cc: Len Brown Signed-off-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memory_hotplug.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/memory_hotplug.h') diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 69903ccf549e..b6a3be7d47bf 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -233,6 +233,7 @@ static inline void unlock_memory_hotplug(void) {} #ifdef CONFIG_MEMORY_HOTREMOVE extern int is_mem_section_removable(unsigned long pfn, unsigned long nr_pages); +extern void try_offline_node(int nid); #else static inline int is_mem_section_removable(unsigned long pfn, @@ -240,6 +241,8 @@ static inline int is_mem_section_removable(unsigned long pfn, { return 0; } + +static inline void try_offline_node(int nid) {} #endif /* CONFIG_MEMORY_HOTREMOVE */ extern int mem_online_node(int nid); -- cgit v1.2.3