swsusp: use rbtree for tracking allocated swap
Make swsusp use extents instead of a bitmap to trace swap pages allocated
for saving the image (the tracking is only needed in case there's an error,
so that the allocated swap pages can be released).
This should allow us to reduce the memory usage, practically always, and
improve performance.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index b18c155..e83ed99 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -243,7 +243,6 @@
struct swap_map_handle {
struct swap_map_page *cur;
sector_t cur_swap;
- struct bitmap_page *bitmap;
unsigned int k;
};
@@ -252,9 +251,6 @@
if (handle->cur)
free_page((unsigned long)handle->cur);
handle->cur = NULL;
- if (handle->bitmap)
- free_bitmap(handle->bitmap);
- handle->bitmap = NULL;
}
static int get_swap_writer(struct swap_map_handle *handle)
@@ -262,12 +258,7 @@
handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
if (!handle->cur)
return -ENOMEM;
- handle->bitmap = alloc_bitmap(count_swap_pages(root_swap, 0));
- if (!handle->bitmap) {
- release_swap_writer(handle);
- return -ENOMEM;
- }
- handle->cur_swap = alloc_swapdev_block(root_swap, handle->bitmap);
+ handle->cur_swap = alloc_swapdev_block(root_swap);
if (!handle->cur_swap) {
release_swap_writer(handle);
return -ENOSPC;
@@ -284,7 +275,7 @@
if (!handle->cur)
return -EINVAL;
- offset = alloc_swapdev_block(root_swap, handle->bitmap);
+ offset = alloc_swapdev_block(root_swap);
error = write_page(buf, offset, bio_chain);
if (error)
return error;
@@ -293,7 +284,7 @@
error = wait_on_bio_chain(bio_chain);
if (error)
goto out;
- offset = alloc_swapdev_block(root_swap, handle->bitmap);
+ offset = alloc_swapdev_block(root_swap);
if (!offset)
return -ENOSPC;
handle->cur->next_swap = offset;
@@ -430,7 +421,8 @@
}
}
if (error)
- free_all_swap_pages(root_swap, handle.bitmap);
+ free_all_swap_pages(root_swap);
+
release_swap_writer(&handle);
out:
swsusp_close();
