diff options
| -rw-r--r-- | kernel/power/power.h | 3 | ||||
| -rw-r--r-- | kernel/power/snapshot.c | 602 | ||||
| -rw-r--r-- | kernel/power/swsusp.c | 5 |
3 files changed, 540 insertions, 70 deletions
diff --git a/kernel/power/power.h b/kernel/power/power.h index e18ba20..6e9e2ac 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -109,9 +109,10 @@ struct snapshot_handle { */ #define data_of(handle) ((handle).buffer + (handle).buf_offset) +extern unsigned int snapshot_additional_pages(struct zone *zone); extern int snapshot_read_next(struct snapshot_handle *handle, size_t count); extern int snapshot_write_next(struct snapshot_handle *handle, size_t count); -int snapshot_image_loaded(struct snapshot_handle *handle); +extern int snapshot_image_loaded(struct snapshot_handle *handle); #define SNAPSHOT_IOC_MAGIC '3' #define SNAPSHOT_FREEZE _IO(SNAPSHOT_IOC_MAGIC, 1) diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index d0d691f..852e0df 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -211,6 +211,467 @@ static inline void free_image_page(void *addr, int clear_nosave_free) free_page((unsigned long)addr); } +/* struct linked_page is used to build chains of pages */ + +#define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *)) + +struct linked_page { + struct linked_page *next; + char data[LINKED_PAGE_DATA_SIZE]; +} __attribute__((packed)); + +static inline void +free_list_of_pages(struct linked_page *list, int clear_page_nosave) +{ + while (list) { + struct linked_page *lp = list->next; + + free_image_page(list, clear_page_nosave); + list = lp; + } +} + +/** + * struct chain_allocator is used for allocating small objects out of + * a linked list of pages called 'the chain'. + * + * The chain grows each time when there is no room for a new object in + * the current page. The allocated objects cannot be freed individually. + * It is only possible to free them all at once, by freeing the entire + * chain. + * + * NOTE: The chain allocator may be inefficient if the allocated objects + * are not much smaller than PAGE_SIZE. + */ + +struct chain_allocator { + struct linked_page *chain; /* the chain */ + unsigned int used_space; /* total size of objects allocated out + * of the current page + */ + gfp_t gfp_mask; /* mask for allocating pages */ + int safe_needed; /* if set, only "safe" pages are allocated */ +}; + +static void +chain_init(struct chain_allocator *ca, gfp_t gfp_mask, int safe_needed) +{ + ca->chain = NULL; + ca->used_space = LINKED_PAGE_DATA_SIZE; + ca->gfp_mask = gfp_mask; + ca->safe_needed = safe_needed; +} + +static void *chain_alloc(struct chain_allocator *ca, unsigned int size) +{ + void *ret; + + if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) { + struct linked_page *lp; + + lp = alloc_image_page(ca->gfp_mask, ca->safe_needed); + if (!lp) + return NULL; + + lp->next = ca->chain; + ca->chain = lp; + ca->used_space = 0; + } + ret = ca->chain->data + ca->used_space; + ca->used_space += size; + return ret; +} + +static void chain_free(struct chain_allocator *ca, int clear_page_nosave) +{ + free_list_of_pages(ca->chain, clear_page_nosave); + memset(ca, 0, sizeof(struct chain_allocator)); +} + +/** + * Data types related to memory bitmaps. + * + * Memory bitmap is a structure consiting of many linked lists of + * objects. The main list's elements are of type struct zone_bitmap + * and each of them corresonds to one zone. For each zone bitmap + * object there is a list of objects of type struct bm_block that + * represent each blocks of bit chunks in which information is + * stored. + * + * struct memory_bitmap contains a pointer to the main list of zone + * bitmap objects, a struct bm_position used for browsing the bitmap, + * and a pointer to the list of pages used for allocating all of the + * zone bitmap objects and bitmap block objects. + * + * NOTE: It has to be possible to lay out the bitmap in memory + * using only allocations of order 0. Additionally, the bitmap is + * designed to work with arbitrary number of zones (this is over the + * top for now, but let's avoid making unnecessary assumptions ;-). + * + * struct zone_bitmap contains a pointer to a list of bitmap block + * objects and a pointer to the bitmap block object that has been + * most recently used for setting bits. Additionally, it contains the + * pfns that correspond to the start and end of the represented zone. + * + * struct bm_block contains a pointer to the memory page in which + * information is stored (in the form of a block of bit chunks + * of type unsigned long each). It also contains the pfns that + * correspond to the start and end of the represented memory area and + * the number of bit chunks in the block. + * + * NOTE: Memory bitmaps are used for two types of operations only: + * "set a bit" and "find the next bit set". Moreover, the searching + * is always carried out after all of the "set a bit" operations + * on given bitmap. + */ + +#define BM_END_OF_MAP (~0UL) + +#define BM_CHUNKS_PER_BLOCK (PAGE_SIZE / sizeof(long)) +#define BM_BITS_PER_CHUNK (sizeof(long) << 3) +#define BM_BITS_PER_BLOCK (PAGE_SIZE << 3) + +struct bm_block { + struct bm_block *next; /* next element of the list */ + unsigned long start_pfn; /* pfn represented by the first bit */ + unsigned long end_pfn; /* pfn represented by the last bit plus 1 */ + unsigned int size; /* number of bit chunks */ + unsigned long *data; /* chunks of bits representing pages */ +}; + +struct zone_bitmap { + struct zone_bitmap *next; /* next element of the list */ + unsigned long start_pfn; /* minimal pfn in this zone */ + unsigned long end_pfn; /* maximal pfn in this zone plus 1 */ + struct bm_block *bm_blocks; /* list of bitmap blocks */ + struct bm_block *cur_block; /* recently used bitmap block */ +}; + +/* strcut bm_position is used for browsing memory bitmaps */ + +struct bm_position { + struct zone_bitmap *zone_bm; + struct bm_block *block; + int chunk; + int bit; +}; + +struct memory_bitmap { + struct zone_bitmap *zone_bm_list; /* list of zone bitmaps */ + struct linked_page *p_list; /* list of pages used to store zone + * bitmap objects and bitmap block + * objects + */ + struct bm_position cur; /* most recently used bit position */ +}; + +/* Functions that operate on memory bitmaps */ + +static inline void memory_bm_reset_chunk(struct memory_bitmap *bm) +{ + bm->cur.chunk = 0; + bm->cur.bit = -1; +} + +static void memory_bm_position_reset(struct memory_bitmap *bm) +{ + struct zone_bitmap *zone_bm; + + zone_bm = bm->zone_bm_list; + bm->cur.zone_bm = zone_bm; + bm->cur.block = zone_bm->bm_blocks; + memory_bm_reset_chunk(bm); +} + +static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free); + +/** + * create_bm_block_list - create a list of block bitmap objects + */ + +static inline struct bm_block * +create_bm_block_list(unsigned int nr_blocks, struct chain_allocator *ca) +{ + struct bm_block *bblist = NULL; + + while (nr_blocks-- > 0) { + struct bm_block *bb; + + bb = chain_alloc(ca, sizeof(struct bm_block)); + if (!bb) + return NULL; + + bb->next = bblist; + bblist = bb; + } + return bblist; +} + +/** + * create_zone_bm_list - create a list of zone bitmap objects + */ + +static inline struct zone_bitmap * +create_zone_bm_list(unsigned int nr_zones, struct chain_allocator *ca) +{ + struct zone_bitmap *zbmlist = NULL; + + while (nr_zones-- > 0) { + struct zone_bitmap *zbm; + + zbm = chain_alloc(ca, sizeof(struct zone_bitmap)); + if (!zbm) + return NULL; + + zbm->next = zbmlist; + zbmlist = zbm; + } + return zbmlist; +} + +/** + * memory_bm_create - allocate memory for a memory bitmap + */ + +static int +memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask, int safe_needed) +{ + struct chain_allocator ca; + struct zone *zone; + struct zone_bitmap *zone_bm; + struct bm_block *bb; + unsigned int nr; + + chain_init(&ca, gfp_mask, safe_needed); + + /* Compute the number of zones */ + nr = 0; + for_each_zone (zone) + if (populated_zone(zone) && !is_highmem(zone)) + nr++; + + /* Allocate the list of zones bitmap objects */ + zone_bm = create_zone_bm_list(nr, &ca); + bm->zone_bm_list = zone_bm; + if (!zone_bm) { + chain_free(&ca, PG_UNSAFE_CLEAR); + return -ENOMEM; + } + + /* Initialize the zone bitmap objects */ + for_each_zone (zone) { + unsigned long pfn; + + if (!populated_zone(zone) || is_highmem(zone)) + continue; + + zone_bm->start_pfn = zone->zone_start_pfn; + zone_bm->end_pfn = zone->zone_start_pfn + zone->spanned_pages; + /* Allocate the list of bitmap block objects */ + nr = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK); + bb = create_bm_block_list(nr, &ca); + zone_bm->bm_blocks = bb; + zone_bm->cur_block = bb; + if (!bb) + goto Free; + + nr = zone->spanned_pages; + pfn = zone->zone_start_pfn; + /* Initialize the bitmap block objects */ + while (bb) { + unsigned long *ptr; + + ptr = alloc_image_page(gfp_mask, safe_needed); + bb->data = ptr; + if (!ptr) + goto Free; + + bb->start_pfn = pfn; + if (nr >= BM_BITS_PER_BLOCK) { + pfn += BM_BITS_PER_BLOCK; + bb->size = BM_CHUNKS_PER_BLOCK; + nr -= BM_BITS_PER_BLOCK; + } else { + /* This is executed only once in the loop */ + pfn += nr; + bb->size = DIV_ROUND_UP(nr, BM_BITS_PER_CHUNK); + } + bb->end_pfn = pfn; + bb = bb->next; + } + zone_bm = zone_bm->next; + } + bm->p_list = ca.chain; + memory_bm_position_reset(bm); + return 0; + +Free: + bm->p_list = ca.chain; + memory_bm_free(bm, PG_UNSAFE_CLEAR); + return -ENOMEM; +} + +/** + * memory_bm_free - free memory occupied by the memory bitmap @bm + */ + +static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free) +{ + struct zone_bitmap *zone_bm; + + /* Free the list of bit blocks for each zone_bitmap object */ + zone_bm = bm->zone_bm_list; + while (zone_bm) { + struct bm_block *bb; + + bb = zone_bm->bm_blocks; + while (bb) { + if (bb->data) + free_image_page(bb->data, clear_nosave_free); + bb = bb->next; + } + zone_bm = zone_bm->next; + } + free_list_of_pages(bm->p_list, clear_nosave_free); + bm->zone_bm_list = NULL; +} + +/** + * memory_bm_set_bit - set the bit in the bitmap @bm that corresponds + * to given pfn. The cur_zone_bm member of @bm and the cur_block member + * of @bm->cur_zone_bm are updated. + * + * If the bit cannot be set, the function returns -EINVAL . + */ + +static int +memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn) +{ + struct zone_bitmap *zone_bm; + struct bm_block *bb; + + /* Check if the pfn is from the current zone */ + zone_bm = bm->cur.zone_bm; + if (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) { + zone_bm = bm->zone_bm_list; + /* We don't assume that the zones are sorted by pfns */ + while (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) { + zone_bm = zone_bm->next; + if (unlikely(!zone_bm)) + return -EINVAL; + } + bm->cur.zone_bm = zone_bm; + } + /* Check if the pfn corresponds to the current bitmap block */ + bb = zone_bm->cur_block; + if (pfn < bb->start_pfn) + bb = zone_bm->bm_blocks; + + while (pfn >= bb->end_pfn) { + bb = bb->next; + if (unlikely(!bb)) + return -EINVAL; + } + zone_bm->cur_block = bb; + pfn -= bb->start_pfn; + set_bit(pfn % BM_BITS_PER_CHUNK, bb->data + pfn / BM_BITS_PER_CHUNK); + return 0; +} + +/* Two auxiliary functions for memory_bm_next_pfn */ + +/* Find the first set bit in the given chunk, if there is one */ + +static inline int next_bit_in_chunk(int bit, unsigned long *chunk_p) +{ + bit++; + while (bit < BM_BITS_PER_CHUNK) { + if (test_bit(bit, chunk_p)) + return bit; + + bit++; + } + return -1; +} + +/* Find a chunk containing some bits set in given block of bits */ + +static inline int next_chunk_in_block(int n, struct bm_block *bb) +{ + n++; + while (n < bb->size) { + if (bb->data[n]) + return n; + + n++; + } + return -1; +} + +/** + * memory_bm_next_pfn - find the pfn that corresponds to the next set bit + * in the bitmap @bm. If the pfn cannot be found, BM_END_OF_MAP is + * returned. + * + * It is required to run memory_bm_position_reset() before the first call to + * this function. + */ + +static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm) +{ + struct zone_bitmap *zone_bm; + struct bm_block *bb; + int chunk; + int bit; + + do { + bb = bm->cur.block; + do { + chunk = bm->cur.chunk; + bit = bm->cur.bit; + do { + bit = next_bit_in_chunk(bit, bb->data + chunk); + if (bit >= 0) + goto Return_pfn; + + chunk = next_chunk_in_block(chunk, bb); + bit = -1; + } while (chunk >= 0); + bb = bb->next; + bm->cur.block = bb; + memory_bm_reset_chunk(bm); + } while (bb); + zone_bm = bm->cur.zone_bm->next; + if (zone_bm) { + bm->cur.zone_bm = zone_bm; + bm->cur.block = zone_bm->bm_blocks; + memory_bm_reset_chunk(bm); + } + } while (zone_bm); + memory_bm_position_reset(bm); + return BM_END_OF_MAP; + +Return_pfn: + bm->cur.chunk = chunk; + bm->cur.bit = bit; + return bb->start_pfn + chunk * BM_BITS_PER_CHUNK + bit; +} + +/** + * snapshot_additional_pages - estimate the number of additional pages + * be needed for setting up the suspend image data structures for given + * zone (usually the returned value is greater than the exact number) + */ + +unsigned int snapshot_additional_pages(struct zone *zone) +{ + unsigned int res; + + res = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK); + res += DIV_ROUND_UP(res * sizeof(struct bm_block), PAGE_SIZE); + return res; +} + /** * pfn_is_nosave - check if given pfn is in the 'nosave' section */ @@ -276,32 +737,38 @@ static inline void copy_data_page(long *dst, long *src) *dst++ = *src++; } -static void copy_data_pages(struct pbe *pblist) +static void +copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm) { struct zone *zone; - unsigned long pfn, max_zone_pfn; - struct pbe *pbe; + unsigned long pfn; - pbe = pblist; for_each_zone (zone) { + unsigned long max_zone_pfn; + if (is_highmem(zone)) continue; + mark_free_pages(zone); max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; - for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) { - struct page *page = saveable_page(pfn); - - if (page) { - void *ptr = page_address(page); - - BUG_ON(!pbe); - copy_data_page((void *)pbe->address, ptr); - pbe->orig_address = (unsigned long)ptr; - pbe = pbe->next; - } - } + for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) + if (saveable_page(pfn)) + memory_bm_set_bit(orig_bm, pfn); } - BUG_ON(pbe); + memory_bm_position_reset(orig_bm); + memory_bm_position_reset(copy_bm); + do { + pfn = memory_bm_next_pfn(orig_bm); + if (likely(pfn != BM_END_OF_MAP)) { + struct page *page; + void *src; + + page = pfn_to_page(pfn); + src = page_address(page); + page = pfn_to_page(memory_bm_next_pfn(copy_bm)); + copy_data_page(page_address(page), src); + } + } while (pfn != BM_END_OF_MAP); } /** @@ -447,37 +914,43 @@ static int enough_free_mem(unsigned int nr_pages) (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE); } -static int alloc_data_pages(struct pbe *pblist, gfp_t gfp_mask, int safe_needed) +static int +swsusp_alloc(struct memory_bitmap *orig_bm, struct memory_bitmap *copy_bm, + unsigned int nr_pages) { - struct pbe *p; + int error; - for_each_pbe (p, pblist) { - p->address = (unsigned long)alloc_image_page(gfp_mask, safe_needed); - if (!p->address) - return -ENOMEM; - } - return 0; -} + error = memory_bm_create(orig_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY); + if (error) + goto Free; -static struct pbe *swsusp_alloc(unsigned int nr_pages) -{ - struct pbe *pblist; + error = memory_bm_create(copy_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY); + if (error) + goto Free; - pblist = alloc_pagedir(nr_pages, GFP_ATOMIC | __GFP_COLD, PG_ANY); - if (!pblist) { - printk(KERN_ERR "suspend: Allocating pagedir failed.\n"); - return NULL; - } + while (nr_pages-- > 0) { + struct page *page = alloc_page(GFP_ATOMIC | __GFP_COLD); + if (!page) + goto Free; - if (alloc_data_pages(pblist, GFP_ATOMIC | __GFP_COLD, PG_ANY)) { - printk(KERN_ERR "suspend: Allocating image pages failed.\n"); - swsusp_free(); - return NULL; + SetPageNosave(page); + SetPageNosaveFree(page); + memory_bm_set_bit(copy_bm, page_to_pfn(page)); } + return 0; - return pblist; +Free: + swsusp_free(); + return -ENOMEM; } +/* Memory bitmap used for marking saveable pages */ +static struct memory_bitmap orig_bm; +/* Memory bitmap used for marking allocated pages that will contain the copies + * of saveable pages + */ +static struct memory_bitmap copy_bm; + asmlinkage int swsusp_save(void) { unsigned int nr_pages; @@ -498,15 +971,14 @@ asmlinkage int swsusp_save(void) return -ENOMEM; } - restore_pblist = swsusp_alloc(nr_pages); - if (!restore_pblist) + if (swsusp_alloc(&orig_bm, ©_bm, nr_pages)) return -ENOMEM; /* During allocating of suspend pagedir, new cold pages may appear. * Kill them. */ drain_local_pages(); - copy_data_pages(restore_pblist); + copy_data_pages(©_bm, &orig_bm); /* * End of critical section. From now on, we can write to memory, @@ -535,22 +1007,23 @@ static void init_header(struct swsusp_info *info) } /** - * pack_orig_addresses - the .orig_address fields of the PBEs from the - * list starting at @pbe are stored in the array @buf[] (1 page) + * pack_addresses - the addresses corresponding to pfns found in the + * bitmap @bm are stored in the array @buf[] (1 page) */ -static inline struct pbe *pack_orig_addresses(unsigned long *buf, struct pbe *pbe) +static inline void +pack_addresses(unsigned long *buf, struct memory_bitmap *bm) { int j; - for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) { - buf[j] = pbe->orig_address; - pbe = pbe->next; + for (j = 0; j < PAGE_SIZE / sizeof(long); j++) { + unsigned long pfn = memory_bm_next_pfn(bm); + + if (unlikely(pfn == BM_END_OF_MAP)) + break; + + buf[j] = (unsigned long)page_address(pfn_to_page(pfn)); } - if (!pbe) - for (; j < PAGE_SIZE / sizeof(long); j++) - buf[j] = 0; - return pbe; } /** @@ -579,6 +1052,7 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count) { if (handle->cur > nr_meta_pages + nr_copy_pages) return 0; + if (!buffer) { /* This makes the buffer be freed by swsusp_free() */ buffer = alloc_image_page(GFP_ATOMIC, PG_ANY); @@ -588,16 +1062,17 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count) if (!handle->offset) { init_header((struct swsusp_info *)buffer); handle->buffer = buffer; - handle->pbe = restore_pblist; + memory_bm_position_reset(&orig_bm); + memory_bm_position_reset(©_bm); } if (handle->prev < handle->cur) { if (handle->cur <= nr_meta_pages) { - handle->pbe = pack_orig_addresses(buffer, handle->pbe); - if (!handle->pbe) - handle->pbe = restore_pblist; + memset(buffer, 0, PAGE_SIZE); + pack_addresses(buffer, &orig_bm); } else { - handle->buffer = (void *)handle->pbe->address; - handle->pbe = handle->pbe->next; + unsigned long pfn = memory_bm_next_pfn(©_bm); + + handle->buffer = page_address(pfn_to_page(pfn)); } handle->prev = handle->cur; } @@ -736,12 +1211,7 @@ static inline struct pbe *unpack_orig_addresses(unsigned long *buf, * of "safe" which will be used later */ -struct safe_page { - struct safe_page *next; - char padding[PAGE_SIZE - sizeof(void *)]; -}; - -static struct safe_page *safe_pages; +static struct linked_page *safe_pages; static int prepare_image(struct snapshot_handle *handle) { @@ -763,9 +1233,9 @@ static int prepare_image(struct snapshot_handle *handle) if (!error && nr_pages > unsafe_pages) { nr_pages -= unsafe_pages; while (nr_pages--) { - struct safe_page *ptr; + struct linked_page *ptr; - ptr = (struct safe_page *)get_zeroed_page(GFP_ATOMIC); + ptr = (void *)get_zeroed_page(GFP_ATOMIC); if (!ptr) { error = -ENOMEM; break; diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c index 17f669c..8ef677e 100644 --- a/kernel/power/swsusp.c +++ b/kernel/power/swsusp.c @@ -193,14 +193,13 @@ int swsusp_shrink_memory(void) printk("Shrinking memory... "); do { size = 2 * count_highmem_pages(); - size += size / 50 + count_data_pages(); - size += (size + PBES_PER_PAGE - 1) / PBES_PER_PAGE + - PAGES_FOR_IO; + size += size / 50 + count_data_pages() + PAGES_FOR_IO; tmp = size; for_each_zone (zone) if (!is_highmem(zone) && populated_zone(zone)) { tmp -= zone->free_pages; tmp += zone->lowmem_reserve[ZONE_NORMAL]; + tmp += snapshot_additional_pages(zone); } if (tmp > 0) { tmp = __shrink_memory(tmp); |