diff options
Diffstat (limited to 'include/linux/mm.h')
| -rw-r--r-- | include/linux/mm.h | 55 |
1 files changed, 33 insertions, 22 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 237b3ba29225..65db4aee738a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -138,7 +138,6 @@ extern unsigned int kobjsize(const void *objp); #define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */ #define VM_NORESERVE 0x00200000 /* should the VM suppress accounting */ #define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */ -#define VM_NONLINEAR 0x00800000 /* Is non-linear (remap_file_pages) */ #define VM_ARCH_1 0x01000000 /* Architecture-specific flag */ #define VM_ARCH_2 0x02000000 #define VM_DONTDUMP 0x04000000 /* Do not include in the core dump */ @@ -206,21 +205,19 @@ extern unsigned int kobjsize(const void *objp); extern pgprot_t protection_map[16]; #define FAULT_FLAG_WRITE 0x01 /* Fault was a write access */ -#define FAULT_FLAG_NONLINEAR 0x02 /* Fault was via a nonlinear mapping */ -#define FAULT_FLAG_MKWRITE 0x04 /* Fault was mkwrite of existing pte */ -#define FAULT_FLAG_ALLOW_RETRY 0x08 /* Retry fault if blocking */ -#define FAULT_FLAG_RETRY_NOWAIT 0x10 /* Don't drop mmap_sem and wait when retrying */ -#define FAULT_FLAG_KILLABLE 0x20 /* The fault task is in SIGKILL killable region */ -#define FAULT_FLAG_TRIED 0x40 /* second try */ -#define FAULT_FLAG_USER 0x80 /* The fault originated in userspace */ +#define FAULT_FLAG_MKWRITE 0x02 /* Fault was mkwrite of existing pte */ +#define FAULT_FLAG_ALLOW_RETRY 0x04 /* Retry fault if blocking */ +#define FAULT_FLAG_RETRY_NOWAIT 0x08 /* Don't drop mmap_sem and wait when retrying */ +#define FAULT_FLAG_KILLABLE 0x10 /* The fault task is in SIGKILL killable region */ +#define FAULT_FLAG_TRIED 0x20 /* Second try */ +#define FAULT_FLAG_USER 0x40 /* The fault originated in userspace */ /* * vm_fault is filled by the the pagefault handler and passed to the vma's * ->fault function. The vma's ->fault is responsible for returning a bitmask * of VM_FAULT_xxx flags that give details about how the fault was handled. * - * pgoff should be used in favour of virtual_address, if possible. If pgoff - * is used, one may implement ->remap_pages to get nonlinear mapping support. + * pgoff should be used in favour of virtual_address, if possible. */ struct vm_fault { unsigned int flags; /* FAULT_FLAG_xxx flags */ @@ -287,10 +284,6 @@ struct vm_operations_struct { struct mempolicy *(*get_policy)(struct vm_area_struct *vma, unsigned long addr); #endif - /* called by sys_remap_file_pages() to populate non-linear mapping */ - int (*remap_pages)(struct vm_area_struct *vma, unsigned long addr, - unsigned long size, pgoff_t pgoff); - /* * Called by vm_normal_page() for special PTEs to find the * page for @addr. This is useful if the default behavior @@ -454,6 +447,12 @@ static inline struct page *compound_head_by_tail(struct page *tail) return tail; } +/* + * Since either compound page could be dismantled asynchronously in THP + * or we access asynchronously arbitrary positioned struct page, there + * would be tail flag race. To handle this race, we should call + * smp_rmb() before checking tail flag. compound_head_by_tail() did it. + */ static inline struct page *compound_head(struct page *page) { if (unlikely(PageTail(page))) @@ -462,6 +461,18 @@ static inline struct page *compound_head(struct page *page) } /* + * If we access compound page synchronously such as access to + * allocated page, there is no need to handle tail flag race, so we can + * check tail flag directly without any synchronization primitive. + */ +static inline struct page *compound_head_fast(struct page *page) +{ + if (unlikely(PageTail(page))) + return page->first_page; + return page; +} + +/* * The atomic page->_mapcount, starts from -1: so that transitions * both from it and to it can be tracked, using atomic_inc_and_test * and atomic_add_negative(-1). @@ -539,7 +550,14 @@ static inline void get_page(struct page *page) static inline struct page *virt_to_head_page(const void *x) { struct page *page = virt_to_page(x); - return compound_head(page); + + /* + * We don't need to worry about synchronization of tail flag + * when we call virt_to_head_page() since it is only called for + * already allocated page and this page won't be freed until + * this virt_to_head_page() is finished. So use _fast variant. + */ + return compound_head_fast(page); } /* @@ -1129,7 +1147,6 @@ extern void user_shm_unlock(size_t, struct user_struct *); * Parameter block passed down to zap_pte_range in exceptional cases. */ struct zap_details { - struct vm_area_struct *nonlinear_vma; /* Check page->index if set */ struct address_space *check_mapping; /* Check page->mapping if set */ pgoff_t first_index; /* Lowest page->index to unmap */ pgoff_t last_index; /* Highest page->index to unmap */ @@ -1785,12 +1802,6 @@ struct vm_area_struct *vma_interval_tree_iter_next(struct vm_area_struct *node, for (vma = vma_interval_tree_iter_first(root, start, last); \ vma; vma = vma_interval_tree_iter_next(vma, start, last)) -static inline void vma_nonlinear_insert(struct vm_area_struct *vma, - struct list_head *list) -{ - list_add_tail(&vma->shared.nonlinear, list); -} - void anon_vma_interval_tree_insert(struct anon_vma_chain *node, struct rb_root *root); void anon_vma_interval_tree_remove(struct anon_vma_chain *node, |
