Messages in this thread Patch in this message | | | Date | Wed, 27 Jun 2012 14:44:17 +0900 | From | Yasuaki Ishimatsu <> | Subject | [RFC PATCH 2/12] memory-hogplug : check memory offline in offline_pages |
| |
When offline_pages() is called to offlined memory, the function fails since all memory has been offlined. In this case, the function should succeed. The patch adds the check function into offline_pages().
CC: Len Brown <len.brown@intel.com> CC: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> CC: Christoph Lameter <cl@linux.com> Cc: Minchan Kim <minchan.kim@gmail.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> CC: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
--- drivers/base/memory.c | 20 ++++++++++++++++++++ include/linux/memory.h | 1 + mm/memory_hotplug.c | 5 +++++ 3 files changed, 26 insertions(+)
Index: linux-3.5-rc4/drivers/base/memory.c =================================================================== --- linux-3.5-rc4.orig/drivers/base/memory.c 2012-06-26 13:28:16.726211752 +0900 +++ linux-3.5-rc4/drivers/base/memory.c 2012-06-26 13:34:22.423639904 +0900 @@ -70,6 +70,26 @@ void unregister_memory_isolate_notifier( } EXPORT_SYMBOL(unregister_memory_isolate_notifier);
+bool memory_is_offline(unsigned long start_pfn, unsigned long end_pfn) +{ + struct memory_block *mem; + struct mem_section *section; + unsigned long pfn, section_nr; + + for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + section_nr = pfn_to_section_nr(pfn); + section = __nr_to_section(section_nr); + mem = find_memory_block(section); + if (!mem) + continue; + if (mem->state == MEM_OFFLINE) + continue; + return false; + } + + return true; +} + /* * register_memory - Setup a sysfs device for a memory block */ Index: linux-3.5-rc4/include/linux/memory.h =================================================================== --- linux-3.5-rc4.orig/include/linux/memory.h 2012-06-25 04:53:04.000000000 +0900 +++ linux-3.5-rc4/include/linux/memory.h 2012-06-26 13:34:22.424639891 +0900 @@ -120,6 +120,7 @@ extern int memory_isolate_notify(unsigne extern struct memory_block *find_memory_block_hinted(struct mem_section *, struct memory_block *); extern struct memory_block *find_memory_block(struct mem_section *); +extern bool memory_is_offline(unsigned long start_pfn, unsigned long end_pfn); #define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT) enum mem_add_context { BOOT, HOTPLUG }; #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ Index: linux-3.5-rc4/mm/memory_hotplug.c =================================================================== --- linux-3.5-rc4.orig/mm/memory_hotplug.c 2012-06-26 13:28:16.743211538 +0900 +++ linux-3.5-rc4/mm/memory_hotplug.c 2012-06-26 13:48:38.264940468 +0900 @@ -887,6 +887,11 @@ static int __ref offline_pages(unsigned
lock_memory_hotplug();
+ if (memory_is_offline(start_pfn, end_pfn)) { + ret = 0; + goto out; + } + zone = page_zone(pfn_to_page(start_pfn)); node = zone_to_nid(zone); nr_pages = end_pfn - start_pfn;
| |