diff options
Diffstat (limited to 'include/linux/mm_types.h')
| -rw-r--r-- | include/linux/mm_types.h | 43 |
1 files changed, 34 insertions, 9 deletions
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 3d6baa7d4534..f8d1492a114f 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -28,8 +28,6 @@ struct mem_cgroup; IS_ENABLED(CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK)) #define ALLOC_SPLIT_PTLOCKS (SPINLOCK_SIZE > BITS_PER_LONG/8) -typedef void compound_page_dtor(struct page *); - /* * Each physical page in the system has a struct page associated with * it to keep track of whatever it is we are using the page for at the @@ -113,7 +111,13 @@ struct page { }; }; - /* Third double word block */ + /* + * Third double word block + * + * WARNING: bit 0 of the first word encode PageTail(). That means + * the rest users of the storage space MUST NOT use the bit to + * avoid collision and false-positive PageTail(). + */ union { struct list_head lru; /* Pageout list, eg. active_list * protected by zone->lru_lock ! @@ -131,18 +135,37 @@ struct page { #endif }; - struct slab *slab_page; /* slab fields */ struct rcu_head rcu_head; /* Used by SLAB * when destroying via RCU */ - /* First tail page of compound page */ + /* Tail pages of compound page */ struct { - compound_page_dtor *compound_dtor; - unsigned long compound_order; + unsigned long compound_head; /* If bit zero is set */ + + /* First tail page only */ +#ifdef CONFIG_64BIT + /* + * On 64 bit system we have enough space in struct page + * to encode compound_dtor and compound_order with + * unsigned int. It can help compiler generate better or + * smaller code on some archtectures. + */ + unsigned int compound_dtor; + unsigned int compound_order; +#else + unsigned short int compound_dtor; + unsigned short int compound_order; +#endif }; #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && USE_SPLIT_PMD_PTLOCKS - pgtable_t pmd_huge_pte; /* protected by page->ptl */ + struct { + unsigned long __pad; /* do not overlay pmd_huge_pte + * with compound_head to avoid + * possible bit 0 collision. + */ + pgtable_t pmd_huge_pte; /* protected by page->ptl */ + }; #endif }; @@ -163,7 +186,6 @@ struct page { #endif #endif struct kmem_cache *slab_cache; /* SL[AU]B: Pointer to slab */ - struct page *first_page; /* Compound tail pages */ }; #ifdef CONFIG_MEMCG @@ -486,6 +508,9 @@ struct mm_struct { /* address of the bounds directory */ void __user *bd_addr; #endif +#ifdef CONFIG_HUGETLB_PAGE + atomic_long_t hugetlb_usage; +#endif }; static inline void mm_init_cpumask(struct mm_struct *mm) |