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>
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index e6a5bdf..3dc0552 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 @@
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 @@
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 @@
* 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 @@
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 @@
}
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 @@
}
/**
+ * 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 @@
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)