diff options
Diffstat (limited to 'kernel/power/swsusp.c')
-rw-r--r-- | kernel/power/swsusp.c | 137 |
1 files changed, 73 insertions, 64 deletions
diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c index 1753708..1109023 100644 --- a/kernel/power/swsusp.c +++ b/kernel/power/swsusp.c @@ -50,6 +50,7 @@ #include <linux/syscalls.h> #include <linux/highmem.h> #include <linux/time.h> +#include <linux/rbtree.h> #include "power.h" @@ -74,72 +75,69 @@ static inline unsigned int count_highmem_pages(void) { return 0; } /** * The following functions are used for tracing the allocated * swap pages, so that they can be freed in case of an error. - * - * The functions operate on a linked bitmap structure defined - * in power.h */ -void free_bitmap(struct bitmap_page *bitmap) -{ - struct bitmap_page *bp; +struct swsusp_extent { + struct rb_node node; + unsigned long start; + unsigned long end; +}; - while (bitmap) { - bp = bitmap->next; - free_page((unsigned long)bitmap); - bitmap = bp; - } -} +static struct rb_root swsusp_extents = RB_ROOT; -struct bitmap_page *alloc_bitmap(unsigned int nr_bits) +static int swsusp_extents_insert(unsigned long swap_offset) { - struct bitmap_page *bitmap, *bp; - unsigned int n; - - if (!nr_bits) - return NULL; - - bitmap = (struct bitmap_page *)get_zeroed_page(GFP_KERNEL); - bp = bitmap; - for (n = BITMAP_PAGE_BITS; n < nr_bits; n += BITMAP_PAGE_BITS) { - bp->next = (struct bitmap_page *)get_zeroed_page(GFP_KERNEL); - bp = bp->next; - if (!bp) { - free_bitmap(bitmap); - return NULL; + struct rb_node **new = &(swsusp_extents.rb_node); + struct rb_node *parent = NULL; + struct swsusp_extent *ext; + + /* Figure out where to put the new node */ + while (*new) { + ext = container_of(*new, struct swsusp_extent, node); + parent = *new; + if (swap_offset < ext->start) { + /* Try to merge */ + if (swap_offset == ext->start - 1) { + ext->start--; + return 0; + } + new = &((*new)->rb_left); + } else if (swap_offset > ext->end) { + /* Try to merge */ + if (swap_offset == ext->end + 1) { + ext->end++; + return 0; + } + new = &((*new)->rb_right); + } else { + /* It already is in the tree */ + return -EINVAL; } } - return bitmap; -} - -static int bitmap_set(struct bitmap_page *bitmap, unsigned long bit) -{ - unsigned int n; - - n = BITMAP_PAGE_BITS; - while (bitmap && n <= bit) { - n += BITMAP_PAGE_BITS; - bitmap = bitmap->next; - } - if (!bitmap) - return -EINVAL; - n -= BITMAP_PAGE_BITS; - bit -= n; - n = 0; - while (bit >= BITS_PER_CHUNK) { - bit -= BITS_PER_CHUNK; - n++; - } - bitmap->chunks[n] |= (1UL << bit); + /* Add the new node and rebalance the tree. */ + ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL); + if (!ext) + return -ENOMEM; + + ext->start = swap_offset; + ext->end = swap_offset; + rb_link_node(&ext->node, parent, new); + rb_insert_color(&ext->node, &swsusp_extents); return 0; } -sector_t alloc_swapdev_block(int swap, struct bitmap_page *bitmap) +/** + * alloc_swapdev_block - allocate a swap page and register that it has + * been allocated, so that it can be freed in case of an error. + */ + +sector_t alloc_swapdev_block(int swap) { unsigned long offset; offset = swp_offset(get_swap_page_of_type(swap)); if (offset) { - if (bitmap_set(bitmap, offset)) + if (swsusp_extents_insert(offset)) swap_free(swp_entry(swap, offset)); else return swapdev_block(swap, offset); @@ -147,23 +145,34 @@ sector_t alloc_swapdev_block(int swap, struct bitmap_page *bitmap) return 0; } -void free_all_swap_pages(int swap, struct bitmap_page *bitmap) +/** + * free_all_swap_pages - free swap pages allocated for saving image data. + * It also frees the extents used to register which swap entres had been + * allocated. + */ + +void free_all_swap_pages(int swap) { - unsigned int bit, n; - unsigned long test; - - bit = 0; - while (bitmap) { - for (n = 0; n < BITMAP_PAGE_CHUNKS; n++) - for (test = 1UL; test; test <<= 1) { - if (bitmap->chunks[n] & test) - swap_free(swp_entry(swap, bit)); - bit++; - } - bitmap = bitmap->next; + struct rb_node *node; + + while ((node = swsusp_extents.rb_node)) { + struct swsusp_extent *ext; + unsigned long offset; + + ext = container_of(node, struct swsusp_extent, node); + rb_erase(node, &swsusp_extents); + for (offset = ext->start; offset <= ext->end; offset++) + swap_free(swp_entry(swap, offset)); + + kfree(ext); } } +int swsusp_swap_in_use(void) +{ + return (swsusp_extents.rb_node != NULL); +} + /** * swsusp_show_speed - print the time elapsed between two events represented by * @start and @stop |