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authorBojan Smojver <bojan@rexursive.com>2012-04-24 23:53:28 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-05-07 08:53:35 -0700
commit4da7d6143870a2f81ceaeabdc64e0f74121e35b3 (patch)
treec11dd5aff292c68fe442e4d73943ce490917cc33 /kernel
parentda42136018f3a2e187ab1976f7f0a5768c3bda24 (diff)
downloadlwn-4da7d6143870a2f81ceaeabdc64e0f74121e35b3.tar.gz
lwn-4da7d6143870a2f81ceaeabdc64e0f74121e35b3.zip
PM / Hibernate: fix the number of pages used for hibernate/thaw buffering
commit f8262d476823a7ea1eb497ff9676d1eab2393c75 upstream. Hibernation regression fix, since 3.2. Calculate the number of required free pages based on non-high memory pages only, because that is where the buffers will come from. Commit 081a9d043c983f161b78fdc4671324d1342b86bc introduced a new buffer page allocation logic during hibernation, in order to improve the performance. The amount of pages allocated was calculated based on total amount of pages available, although only non-high memory pages are usable for this purpose. This caused hibernation code to attempt to over allocate pages on platforms that have high memory, which led to hangs. Signed-off-by: Bojan Smojver <bojan@rexursive.com> Signed-off-by: Rafael J. Wysocki <rjw@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/power/swap.c28
1 files changed, 22 insertions, 6 deletions
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 8742fd013a94..eef311a58a64 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -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;
};
@@ -316,8 +333,7 @@ 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:
@@ -352,11 +368,11 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf,
handle->cur_swap = offset;
handle->k = 0;
}
- if (bio_chain && ++handle->written > handle->nr_free_pages) {
+ if (bio_chain && low_free_pages() <= handle->reqd_free_pages) {
error = hib_wait_on_bio_chain(bio_chain);
if (error)
goto out;
- handle->written = 0;
+ handle->reqd_free_pages = reqd_free_pages();
}
out:
return error;
@@ -618,7 +634,7 @@ 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;
+ handle->reqd_free_pages = reqd_free_pages();
/*
* Start the CRC32 thread.