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author | 2010-09-09 23:06:23 +0200 | |
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committer | 2010-10-17 01:57:42 +0200 | |
commit | f996fc9671d088bd5f52a70f18c64bfe3d0e418f (patch) | |
tree | 3d88b5adfa21fc71cbabb9a891d37b0c1ce1c692 /kernel/power/swap.c | |
parent | PM / Runtime: Lenient generic runtime pm callbacks (diff) | |
download | linux-f996fc9671d088bd5f52a70f18c64bfe3d0e418f.tar.gz linux-f996fc9671d088bd5f52a70f18c64bfe3d0e418f.tar.bz2 linux-f996fc9671d088bd5f52a70f18c64bfe3d0e418f.zip |
PM / Hibernate: Compress hibernation image with LZO
Compress hibernation image with LZO in order to save on I/O and
therefore time to hibernate/thaw.
[rjw: Added hibernate=nocompress command line option instead of just
nocompress which would be confusing, fixed a couple of compiler
warnings, fixed kerneldoc comments, minor cleanups.]
Signed-off-by: Bojan Smojver <bojan@rexursive.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'kernel/power/swap.c')
-rw-r--r-- | kernel/power/swap.c | 290 |
1 files changed, 283 insertions, 7 deletions
diff --git a/kernel/power/swap.c b/kernel/power/swap.c index e6a5bdf61a37..3dc0552cddfb 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -24,6 +24,8 @@ #include <linux/swapops.h> #include <linux/pm.h> #include <linux/slab.h> +#include <linux/lzo.h> +#include <linux/vmalloc.h> #include "power.h" @@ -357,6 +359,18 @@ static int swap_writer_finish(struct swap_map_handle *handle, return error; } +/* We need to remember how much compressed data we need to read. */ +#define LZO_HEADER sizeof(size_t) + +/* Number of pages/bytes we'll compress at one time. */ +#define LZO_UNC_PAGES 32 +#define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE) + +/* Number of pages/bytes we need for compressed data (worst case). */ +#define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \ + LZO_HEADER, PAGE_SIZE) +#define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE) + /** * save_image - save the suspend image data */ @@ -404,6 +418,137 @@ static int save_image(struct swap_map_handle *handle, return ret; } + +/** + * save_image_lzo - Save the suspend image data compressed with LZO. + * @handle: Swap mam handle to use for saving the image. + * @snapshot: Image to read data from. + * @nr_to_write: Number of pages to save. + */ +static int save_image_lzo(struct swap_map_handle *handle, + struct snapshot_handle *snapshot, + unsigned int nr_to_write) +{ + unsigned int m; + int ret = 0; + int nr_pages; + int err2; + struct bio *bio; + struct timeval start; + struct timeval stop; + size_t off, unc_len, cmp_len; + unsigned char *unc, *cmp, *wrk, *page; + + page = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH); + if (!page) { + printk(KERN_ERR "PM: Failed to allocate LZO page\n"); + return -ENOMEM; + } + + wrk = vmalloc(LZO1X_1_MEM_COMPRESS); + if (!wrk) { + printk(KERN_ERR "PM: Failed to allocate LZO workspace\n"); + free_page((unsigned long)page); + return -ENOMEM; + } + + unc = vmalloc(LZO_UNC_SIZE); + if (!unc) { + printk(KERN_ERR "PM: Failed to allocate LZO uncompressed\n"); + vfree(wrk); + free_page((unsigned long)page); + return -ENOMEM; + } + + cmp = vmalloc(LZO_CMP_SIZE); + if (!cmp) { + printk(KERN_ERR "PM: Failed to allocate LZO compressed\n"); + vfree(unc); + vfree(wrk); + free_page((unsigned long)page); + return -ENOMEM; + } + + printk(KERN_INFO + "PM: Compressing and saving image data (%u pages) ... ", + nr_to_write); + m = nr_to_write / 100; + if (!m) + m = 1; + nr_pages = 0; + bio = NULL; + do_gettimeofday(&start); + for (;;) { + for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) { + ret = snapshot_read_next(snapshot); + if (ret < 0) + goto out_finish; + + if (!ret) + break; + + memcpy(unc + off, data_of(*snapshot), PAGE_SIZE); + + if (!(nr_pages % m)) + printk(KERN_CONT "\b\b\b\b%3d%%", nr_pages / m); + nr_pages++; + } + + if (!off) + break; + + unc_len = off; + ret = lzo1x_1_compress(unc, unc_len, + cmp + LZO_HEADER, &cmp_len, wrk); + if (ret < 0) { + printk(KERN_ERR "PM: LZO compression failed\n"); + break; + } + + if (unlikely(!cmp_len || + cmp_len > lzo1x_worst_compress(unc_len))) { + printk(KERN_ERR "PM: Invalid LZO compressed length\n"); + ret = -1; + break; + } + + *(size_t *)cmp = cmp_len; + + /* + * Given we are writing one page at a time to disk, we copy + * that much from the buffer, although the last bit will likely + * be smaller than full page. This is OK - we saved the length + * of the compressed data, so any garbage at the end will be + * discarded when we read it. + */ + for (off = 0; off < LZO_HEADER + cmp_len; off += PAGE_SIZE) { + memcpy(page, cmp + off, PAGE_SIZE); + + ret = swap_write_page(handle, page, &bio); + if (ret) + goto out_finish; + } + } + +out_finish: + err2 = hib_wait_on_bio_chain(&bio); + do_gettimeofday(&stop); + if (!ret) + ret = err2; + if (!ret) + printk(KERN_CONT "\b\b\b\bdone\n"); + else + printk(KERN_CONT "\n"); + swsusp_show_speed(&start, &stop, nr_to_write, "Wrote"); + + vfree(cmp); + vfree(unc); + vfree(wrk); + free_page((unsigned long)page); + + return ret; +} + /** * enough_swap - Make sure we have enough swap to save the image. * @@ -411,12 +556,16 @@ static int save_image(struct swap_map_handle *handle, * space avaiable from the resume partition. */ -static int enough_swap(unsigned int nr_pages) +static int enough_swap(unsigned int nr_pages, unsigned int flags) { unsigned int free_swap = count_swap_pages(root_swap, 1); + unsigned int required; pr_debug("PM: Free swap pages: %u\n", free_swap); - return free_swap > nr_pages + PAGES_FOR_IO; + + required = PAGES_FOR_IO + ((flags & SF_NOCOMPRESS_MODE) ? + nr_pages : (nr_pages * LZO_CMP_PAGES) / LZO_UNC_PAGES + 1); + return free_swap > required; } /** @@ -443,7 +592,7 @@ int swsusp_write(unsigned int flags) printk(KERN_ERR "PM: Cannot get swap writer\n"); return error; } - if (!enough_swap(pages)) { + if (!enough_swap(pages, flags)) { printk(KERN_ERR "PM: Not enough free swap\n"); error = -ENOSPC; goto out_finish; @@ -458,8 +607,11 @@ int swsusp_write(unsigned int flags) } header = (struct swsusp_info *)data_of(snapshot); error = swap_write_page(&handle, header, NULL); - if (!error) - error = save_image(&handle, &snapshot, pages - 1); + if (!error) { + error = (flags & SF_NOCOMPRESS_MODE) ? + save_image(&handle, &snapshot, pages - 1) : + save_image_lzo(&handle, &snapshot, pages - 1); + } out_finish: error = swap_writer_finish(&handle, flags, error); return error; @@ -590,6 +742,127 @@ static int load_image(struct swap_map_handle *handle, } /** + * load_image_lzo - Load compressed image data and decompress them with LZO. + * @handle: Swap map handle to use for loading data. + * @snapshot: Image to copy uncompressed data into. + * @nr_to_read: Number of pages to load. + */ +static int load_image_lzo(struct swap_map_handle *handle, + struct snapshot_handle *snapshot, + unsigned int nr_to_read) +{ + unsigned int m; + int error = 0; + struct timeval start; + struct timeval stop; + unsigned nr_pages; + size_t off, unc_len, cmp_len; + unsigned char *unc, *cmp, *page; + + page = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH); + if (!page) { + printk(KERN_ERR "PM: Failed to allocate LZO page\n"); + return -ENOMEM; + } + + unc = vmalloc(LZO_UNC_SIZE); + if (!unc) { + printk(KERN_ERR "PM: Failed to allocate LZO uncompressed\n"); + free_page((unsigned long)page); + return -ENOMEM; + } + + cmp = vmalloc(LZO_CMP_SIZE); + if (!cmp) { + printk(KERN_ERR "PM: Failed to allocate LZO compressed\n"); + vfree(unc); + free_page((unsigned long)page); + return -ENOMEM; + } + + printk(KERN_INFO + "PM: Loading and decompressing image data (%u pages) ... ", + nr_to_read); + m = nr_to_read / 100; + if (!m) + m = 1; + nr_pages = 0; + do_gettimeofday(&start); + + error = snapshot_write_next(snapshot); + if (error <= 0) + goto out_finish; + + for (;;) { + error = swap_read_page(handle, page, NULL); /* sync */ + if (error) + break; + + cmp_len = *(size_t *)page; + if (unlikely(!cmp_len || + cmp_len > lzo1x_worst_compress(LZO_UNC_SIZE))) { + printk(KERN_ERR "PM: Invalid LZO compressed length\n"); + error = -1; + break; + } + + memcpy(cmp, page, PAGE_SIZE); + for (off = PAGE_SIZE; off < LZO_HEADER + cmp_len; off += PAGE_SIZE) { + error = swap_read_page(handle, page, NULL); /* sync */ + if (error) + goto out_finish; + + memcpy(cmp + off, page, PAGE_SIZE); + } + + unc_len = LZO_UNC_SIZE; + error = lzo1x_decompress_safe(cmp + LZO_HEADER, cmp_len, + unc, &unc_len); + if (error < 0) { + printk(KERN_ERR "PM: LZO decompression failed\n"); + break; + } + + if (unlikely(!unc_len || + unc_len > LZO_UNC_SIZE || + unc_len & (PAGE_SIZE - 1))) { + printk(KERN_ERR "PM: Invalid LZO uncompressed length\n"); + error = -1; + break; + } + + for (off = 0; off < unc_len; off += PAGE_SIZE) { + memcpy(data_of(*snapshot), unc + off, PAGE_SIZE); + + if (!(nr_pages % m)) + printk("\b\b\b\b%3d%%", nr_pages / m); + nr_pages++; + + error = snapshot_write_next(snapshot); + if (error <= 0) + goto out_finish; + } + } + +out_finish: + do_gettimeofday(&stop); + if (!error) { + printk("\b\b\b\bdone\n"); + snapshot_write_finalize(snapshot); + if (!snapshot_image_loaded(snapshot)) + error = -ENODATA; + } else + printk("\n"); + swsusp_show_speed(&start, &stop, nr_to_read, "Read"); + + vfree(cmp); + vfree(unc); + free_page((unsigned long)page); + + return error; +} + +/** * swsusp_read - read the hibernation image. * @flags_p: flags passed by the "frozen" kernel in the image header should * be written into this memeory location @@ -612,8 +885,11 @@ int swsusp_read(unsigned int *flags_p) goto end; if (!error) error = swap_read_page(&handle, header, NULL); - if (!error) - error = load_image(&handle, &snapshot, header->pages - 1); + if (!error) { + error = (*flags_p & SF_NOCOMPRESS_MODE) ? + load_image(&handle, &snapshot, header->pages - 1) : + load_image_lzo(&handle, &snapshot, header->pages - 1); + } swap_reader_finish(&handle); end: if (!error) |