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Diffstat (limited to 'kernel/power/swsusp.c')
| -rw-r--r-- | kernel/power/swsusp.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c new file mode 100644 index 0000000..023ff2a --- /dev/null +++ b/kernel/power/swsusp.c @@ -0,0 +1,264 @@ +/* + * linux/kernel/power/swsusp.c + * + * This file provides code to write suspend image to swap and read it back. + * + * Copyright (C) 1998-2001 Gabor Kuti <seasons@fornax.hu> + * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz> + * + * This file is released under the GPLv2. + * + * I'd like to thank the following people for their work: + * + * Pavel Machek <pavel@ucw.cz>: + * Modifications, defectiveness pointing, being with me at the very beginning, + * suspend to swap space, stop all tasks. Port to 2.4.18-ac and 2.5.17. + * + * Steve Doddi <dirk@loth.demon.co.uk>: + * Support the possibility of hardware state restoring. + * + * Raph <grey.havens@earthling.net>: + * Support for preserving states of network devices and virtual console + * (including X and svgatextmode) + * + * Kurt Garloff <garloff@suse.de>: + * Straightened the critical function in order to prevent compilers from + * playing tricks with local variables. + * + * Andreas Mohr <a.mohr@mailto.de> + * + * Alex Badea <vampire@go.ro>: + * Fixed runaway init + * + * Rafael J. Wysocki <rjw@sisk.pl> + * Reworked the freeing of memory and the handling of swap + * + * More state savers are welcome. Especially for the scsi layer... + * + * For TODOs,FIXMEs also look in Documentation/power/swsusp.txt + */ + +#include <linux/mm.h> +#include <linux/suspend.h> +#include <linux/spinlock.h> +#include <linux/kernel.h> +#include <linux/major.h> +#include <linux/swap.h> +#include <linux/pm.h> +#include <linux/swapops.h> +#include <linux/bootmem.h> +#include <linux/syscalls.h> +#include <linux/highmem.h> +#include <linux/time.h> +#include <linux/rbtree.h> + +#include "power.h" + +/* + * Preferred image size in bytes (tunable via /sys/power/image_size). + * When it is set to N, swsusp will do its best to ensure the image + * size will not exceed N bytes, but if that is impossible, it will + * try to create the smallest image possible. + */ +unsigned long image_size = 500 * 1024 * 1024; + +int in_suspend __nosavedata = 0; + +/** + * The following functions are used for tracing the allocated + * swap pages, so that they can be freed in case of an error. + */ + +struct swsusp_extent { + struct rb_node node; + unsigned long start; + unsigned long end; +}; + +static struct rb_root swsusp_extents = RB_ROOT; + +static int swsusp_extents_insert(unsigned long swap_offset) +{ + 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; + } + } + /* 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; +} + +/** + * 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 (swsusp_extents_insert(offset)) + swap_free(swp_entry(swap, offset)); + else + return swapdev_block(swap, offset); + } + return 0; +} + +/** + * 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) +{ + 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 + * + * @nr_pages - number of pages processed between @start and @stop + * @msg - introductory message to print + */ + +void swsusp_show_speed(struct timeval *start, struct timeval *stop, + unsigned nr_pages, char *msg) +{ + s64 elapsed_centisecs64; + int centisecs; + int k; + int kps; + + elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start); + do_div(elapsed_centisecs64, NSEC_PER_SEC / 100); + centisecs = elapsed_centisecs64; + if (centisecs == 0) + centisecs = 1; /* avoid div-by-zero */ + k = nr_pages * (PAGE_SIZE / 1024); + kps = (k * 100) / centisecs; + printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n", + msg, k, + centisecs / 100, centisecs % 100, + kps / 1000, (kps % 1000) / 10); +} + +/** + * swsusp_shrink_memory - Try to free as much memory as needed + * + * ... but do not OOM-kill anyone + * + * Notice: all userland should be stopped before it is called, or + * livelock is possible. + */ + +#define SHRINK_BITE 10000 +static inline unsigned long __shrink_memory(long tmp) +{ + if (tmp > SHRINK_BITE) + tmp = SHRINK_BITE; + return shrink_all_memory(tmp); +} + +int swsusp_shrink_memory(void) +{ + long tmp; + struct zone *zone; + unsigned long pages = 0; + unsigned int i = 0; + char *p = "-\\|/"; + struct timeval start, stop; + + printk(KERN_INFO "PM: Shrinking memory... "); + do_gettimeofday(&start); + do { + long size, highmem_size; + + highmem_size = count_highmem_pages(); + size = count_data_pages() + PAGES_FOR_IO + SPARE_PAGES; + tmp = size; + size += highmem_size; + for_each_zone (zone) + if (populated_zone(zone)) { + tmp += snapshot_additional_pages(zone); + if (is_highmem(zone)) { + highmem_size -= + zone_page_state(zone, NR_FREE_PAGES); + } else { + tmp -= zone_page_state(zone, NR_FREE_PAGES); + tmp += zone->lowmem_reserve[ZONE_NORMAL]; + } + } + + if (highmem_size < 0) + highmem_size = 0; + + tmp += highmem_size; + if (tmp > 0) { + tmp = __shrink_memory(tmp); + if (!tmp) + return -ENOMEM; + pages += tmp; + } else if (size > image_size / PAGE_SIZE) { + tmp = __shrink_memory(size - (image_size / PAGE_SIZE)); + pages += tmp; + } + printk("\b%c", p[i++%4]); + } while (tmp > 0); + do_gettimeofday(&stop); + printk("\bdone (%lu pages freed)\n", pages); + swsusp_show_speed(&start, &stop, pages, "Freed"); + + return 0; +} |
