From 49ac825587f33afec8841b7fab2eb4db775014e6 Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Tue, 26 Oct 2010 14:21:30 -0700 Subject: memory hotplug: unify is_removable and offline detection code Now, sysfs interface of memory hotplug shows whether the section is removable or not. But it checks only migrateype of pages and doesn't check details of cluster of pages. Next, memory hotplug's set_migratetype_isolate() has the same kind of check, too. This patch adds the function __count_unmovable_pages() and makes above 2 checks to use the same logic. Then, is_removable and hotremove code uses the same logic. No changes in the hotremove logic itself. TODO: need to find a way to check RECLAMABLE. But, considering bit, calling shrink_slab() against a range before starting memory hotremove sounds better. If so, this patch's logic doesn't need to be changed. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: KAMEZAWA Hiroyuki Reported-by: Michal Hocko Cc: Wu Fengguang Cc: Mel Gorman Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memory_hotplug.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux/memory_hotplug.h') diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 864035fb8f8a..4307231bd22f 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -70,6 +70,10 @@ extern void online_page(struct page *page); extern int online_pages(unsigned long, unsigned long); extern void __offline_isolated_pages(unsigned long, unsigned long); +#ifdef CONFIG_MEMORY_HOTREMOVE +extern bool is_pageblock_removable_nolock(struct page *page); +#endif /* CONFIG_MEMORY_HOTREMOVE */ + /* reasonably generic interface to expand the physical pages in a zone */ extern int __add_pages(int nid, struct zone *zone, unsigned long start_pfn, unsigned long nr_pages); -- cgit From 20d6c96b5f1cad5c5da4641945ec17a1d9a1afc8 Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Thu, 2 Dec 2010 14:31:19 -0800 Subject: mem-hotplug: introduce {un}lock_memory_hotplug() Presently hwpoison is using lock_system_sleep() to prevent a race with memory hotplug. However lock_system_sleep() is a no-op if CONFIG_HIBERNATION=n. Therefore we need a new lock. Signed-off-by: KOSAKI Motohiro Cc: Andi Kleen Cc: Kamezawa Hiroyuki Suggested-by: Hugh Dickins Acked-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memory_hotplug.h | 6 ++++++ mm/memory-failure.c | 8 ++++---- mm/memory_hotplug.c | 31 ++++++++++++++++++++++++------- 3 files changed, 34 insertions(+), 11 deletions(-) (limited to 'include/linux/memory_hotplug.h') diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 4307231bd22f..31c237a00c48 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -161,6 +161,9 @@ extern void register_page_bootmem_info_node(struct pglist_data *pgdat); extern void put_page_bootmem(struct page *page); #endif +void lock_memory_hotplug(void); +void unlock_memory_hotplug(void); + #else /* ! CONFIG_MEMORY_HOTPLUG */ /* * Stub functions for when hotplug is off @@ -192,6 +195,9 @@ static inline void register_page_bootmem_info_node(struct pglist_data *pgdat) { } +static inline void lock_memory_hotplug(void) {} +static inline void unlock_memory_hotplug(void) {} + #endif /* ! CONFIG_MEMORY_HOTPLUG */ #ifdef CONFIG_MEMORY_HOTREMOVE diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 124324134ff6..46ab2c044b0e 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -51,6 +51,7 @@ #include #include #include +#include #include "internal.h" int sysctl_memory_failure_early_kill __read_mostly = 0; @@ -1230,11 +1231,10 @@ static int get_any_page(struct page *p, unsigned long pfn, int flags) return 1; /* - * The lock_system_sleep prevents a race with memory hotplug, - * because the isolation assumes there's only a single user. + * The lock_memory_hotplug prevents a race with memory hotplug. * This is a big hammer, a better would be nicer. */ - lock_system_sleep(); + lock_memory_hotplug(); /* * Isolate the page, so that it doesn't get reallocated if it @@ -1264,7 +1264,7 @@ static int get_any_page(struct page *p, unsigned long pfn, int flags) ret = 1; } unset_migratetype_isolate(p); - unlock_system_sleep(); + unlock_memory_hotplug(); return ret; } diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 9260314a221e..2c6523af5473 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -34,6 +34,23 @@ #include "internal.h" +DEFINE_MUTEX(mem_hotplug_mutex); + +void lock_memory_hotplug(void) +{ + mutex_lock(&mem_hotplug_mutex); + + /* for exclusive hibernation if CONFIG_HIBERNATION=y */ + lock_system_sleep(); +} + +void unlock_memory_hotplug(void) +{ + unlock_system_sleep(); + mutex_unlock(&mem_hotplug_mutex); +} + + /* add this memory to iomem resource */ static struct resource *register_memory_resource(u64 start, u64 size) { @@ -493,7 +510,7 @@ int mem_online_node(int nid) pg_data_t *pgdat; int ret; - lock_system_sleep(); + lock_memory_hotplug(); pgdat = hotadd_new_pgdat(nid, 0); if (pgdat) { ret = -ENOMEM; @@ -504,7 +521,7 @@ int mem_online_node(int nid) BUG_ON(ret); out: - unlock_system_sleep(); + unlock_memory_hotplug(); return ret; } @@ -516,7 +533,7 @@ int __ref add_memory(int nid, u64 start, u64 size) struct resource *res; int ret; - lock_system_sleep(); + lock_memory_hotplug(); res = register_memory_resource(start, size); ret = -EEXIST; @@ -563,7 +580,7 @@ error: release_memory_resource(res); out: - unlock_system_sleep(); + unlock_memory_hotplug(); return ret; } EXPORT_SYMBOL_GPL(add_memory); @@ -791,7 +808,7 @@ static int offline_pages(unsigned long start_pfn, if (!test_pages_in_a_zone(start_pfn, end_pfn)) return -EINVAL; - lock_system_sleep(); + lock_memory_hotplug(); zone = page_zone(pfn_to_page(start_pfn)); node = zone_to_nid(zone); @@ -880,7 +897,7 @@ repeat: writeback_set_ratelimit(); memory_notify(MEM_OFFLINE, &arg); - unlock_system_sleep(); + unlock_memory_hotplug(); return 0; failed_removal: @@ -891,7 +908,7 @@ failed_removal: undo_isolate_page_range(start_pfn, end_pfn); out: - unlock_system_sleep(); + unlock_memory_hotplug(); return ret; } -- cgit