diff options
| -rw-r--r-- | include/linux/mm.h | 4 | ||||
| -rw-r--r-- | mm/memory_hotplug.c | 8 |
2 files changed, 11 insertions, 1 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 52269e56c514..c54fb96cb1e6 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2715,6 +2715,10 @@ static inline bool debug_pagealloc_enabled_static(void) #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP) extern void __kernel_map_pages(struct page *page, int numpages, int enable); +/* + * When called in DEBUG_PAGEALLOC context, the call should most likely be + * guarded by debug_pagealloc_enabled() or debug_pagealloc_enabled_static() + */ static inline void kernel_map_pages(struct page *page, int numpages, int enable) { diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 0a54ffac8c68..19389cdc16a5 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -574,7 +574,13 @@ EXPORT_SYMBOL_GPL(restore_online_page_callback); void generic_online_page(struct page *page, unsigned int order) { - kernel_map_pages(page, 1 << order, 1); + /* + * Freeing the page with debug_pagealloc enabled will try to unmap it, + * so we should map it first. This is better than introducing a special + * case in page freeing fast path. + */ + if (debug_pagealloc_enabled_static()) + kernel_map_pages(page, 1 << order, 1); __free_pages_core(page, order); totalram_pages_add(1UL << order); #ifdef CONFIG_HIGHMEM |