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-rw-r--r--kernel/power/swap.c84
1 files changed, 58 insertions, 26 deletions
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 8742fd013a94..11e22c068e8b 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -6,7 +6,7 @@
*
* Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
* Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
- * Copyright (C) 2010 Bojan Smojver <bojan@rexursive.com>
+ * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
*
* This file is released under the GPLv2.
*
@@ -51,6 +51,23 @@
#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)
+/*
+ * Number of free pages that are not high.
+ */
+static inline unsigned long low_free_pages(void)
+{
+ return nr_free_pages() - nr_free_highpages();
+}
+
+/*
+ * Number of pages required to be kept free while writing the image. Always
+ * half of all available low pages before the writing starts.
+ */
+static inline unsigned long reqd_free_pages(void)
+{
+ return low_free_pages() / 2;
+}
+
struct swap_map_page {
sector_t entries[MAP_PAGE_ENTRIES];
sector_t next_swap;
@@ -72,7 +89,7 @@ struct swap_map_handle {
sector_t cur_swap;
sector_t first_sector;
unsigned int k;
- unsigned long nr_free_pages, written;
+ unsigned long reqd_free_pages;
u32 crc32;
};
@@ -265,14 +282,17 @@ static int write_page(void *buf, sector_t offset, struct bio **bio_chain)
return -ENOSPC;
if (bio_chain) {
- src = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH);
+ src = (void *)__get_free_page(__GFP_WAIT | __GFP_NOWARN |
+ __GFP_NORETRY);
if (src) {
copy_page(src, buf);
} else {
ret = hib_wait_on_bio_chain(bio_chain); /* Free pages */
if (ret)
return ret;
- src = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH);
+ src = (void *)__get_free_page(__GFP_WAIT |
+ __GFP_NOWARN |
+ __GFP_NORETRY);
if (src) {
copy_page(src, buf);
} else {
@@ -316,8 +336,7 @@ static int get_swap_writer(struct swap_map_handle *handle)
goto err_rel;
}
handle->k = 0;
- handle->nr_free_pages = nr_free_pages() >> 1;
- handle->written = 0;
+ handle->reqd_free_pages = reqd_free_pages();
handle->first_sector = handle->cur_swap;
return 0;
err_rel:
@@ -351,12 +370,17 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf,
clear_page(handle->cur);
handle->cur_swap = offset;
handle->k = 0;
- }
- if (bio_chain && ++handle->written > handle->nr_free_pages) {
- error = hib_wait_on_bio_chain(bio_chain);
- if (error)
- goto out;
- handle->written = 0;
+
+ if (bio_chain && low_free_pages() <= handle->reqd_free_pages) {
+ error = hib_wait_on_bio_chain(bio_chain);
+ if (error)
+ goto out;
+ /*
+ * Recalculate the number of required free pages, to
+ * make sure we never take more than half.
+ */
+ handle->reqd_free_pages = reqd_free_pages();
+ }
}
out:
return error;
@@ -403,8 +427,9 @@ static int swap_writer_finish(struct swap_map_handle *handle,
/* Maximum number of threads for compression/decompression. */
#define LZO_THREADS 3
-/* Maximum number of pages for read buffering. */
-#define LZO_READ_PAGES (MAP_PAGE_ENTRIES * 8)
+/* Minimum/maximum number of pages for read buffering. */
+#define LZO_MIN_RD_PAGES 1024
+#define LZO_MAX_RD_PAGES 8192
/**
@@ -615,12 +640,6 @@ static int save_image_lzo(struct swap_map_handle *handle,
}
/*
- * Adjust number of free pages after all allocations have been done.
- * We don't want to run out of pages when writing.
- */
- handle->nr_free_pages = nr_free_pages() >> 1;
-
- /*
* Start the CRC32 thread.
*/
init_waitqueue_head(&crc->go);
@@ -641,6 +660,12 @@ static int save_image_lzo(struct swap_map_handle *handle,
goto out_clean;
}
+ /*
+ * Adjust the number of required free pages after all allocations have
+ * been done. We don't want to run out of pages when writing.
+ */
+ handle->reqd_free_pages = reqd_free_pages();
+
printk(KERN_INFO
"PM: Using %u thread(s) for compression.\n"
"PM: Compressing and saving image data (%u pages) ... ",
@@ -1051,7 +1076,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
unsigned i, thr, run_threads, nr_threads;
unsigned ring = 0, pg = 0, ring_size = 0,
have = 0, want, need, asked = 0;
- unsigned long read_pages;
+ unsigned long read_pages = 0;
unsigned char **page = NULL;
struct dec_data *data = NULL;
struct crc_data *crc = NULL;
@@ -1063,7 +1088,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
nr_threads = num_online_cpus() - 1;
nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
- page = vmalloc(sizeof(*page) * LZO_READ_PAGES);
+ page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES);
if (!page) {
printk(KERN_ERR "PM: Failed to allocate LZO page\n");
ret = -ENOMEM;
@@ -1128,15 +1153,22 @@ static int load_image_lzo(struct swap_map_handle *handle,
}
/*
- * Adjust number of pages for read buffering, in case we are short.
+ * Set the number of pages for read buffering.
+ * This is complete guesswork, because we'll only know the real
+ * picture once prepare_image() is called, which is much later on
+ * during the image load phase. We'll assume the worst case and
+ * say that none of the image pages are from high memory.
*/
- read_pages = (nr_free_pages() - snapshot_get_image_size()) >> 1;
- read_pages = clamp_val(read_pages, LZO_CMP_PAGES, LZO_READ_PAGES);
+ if (low_free_pages() > snapshot_get_image_size())
+ read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
+ read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
for (i = 0; i < read_pages; i++) {
page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
__GFP_WAIT | __GFP_HIGH :
- __GFP_WAIT);
+ __GFP_WAIT | __GFP_NOWARN |
+ __GFP_NORETRY);
+
if (!page[i]) {
if (i < LZO_CMP_PAGES) {
ring_size = i;
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-07-11 05:24:50 +0200