提交 6715045d 编写于 作者: R Rafael J. Wysocki

PM / Hibernate: Avoid hitting OOM during preallocation of memory

There is a problem in hibernate_preallocate_memory() that it calls
preallocate_image_memory() with an argument that may be greater than
the total number of available non-highmem memory pages.  If that's
the case, the OOM condition is guaranteed to trigger, which in turn
can cause significant slowdown to occur during hibernation.

To avoid that, make preallocate_image_memory() adjust its argument
before calling preallocate_image_pages(), so that the total number of
saveable non-highem pages left is not less than the minimum size of
a hibernation image.  Change hibernate_preallocate_memory() to try to
allocate from highmem if the number of pages allocated by
preallocate_image_memory() is too low.

Modify free_unnecessary_pages() to take all possible memory
allocation patterns into account.
Reported-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Tested-by: NM. Vefa Bicakci <bicave@superonline.com>
上级 0109c2c4
......@@ -1122,9 +1122,19 @@ static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask)
return nr_alloc;
}
static unsigned long preallocate_image_memory(unsigned long nr_pages)
static unsigned long preallocate_image_memory(unsigned long nr_pages,
unsigned long avail_normal)
{
return preallocate_image_pages(nr_pages, GFP_IMAGE);
unsigned long alloc;
if (avail_normal <= alloc_normal)
return 0;
alloc = avail_normal - alloc_normal;
if (nr_pages < alloc)
alloc = nr_pages;
return preallocate_image_pages(alloc, GFP_IMAGE);
}
#ifdef CONFIG_HIGHMEM
......@@ -1170,15 +1180,22 @@ static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
*/
static void free_unnecessary_pages(void)
{
unsigned long save_highmem, to_free_normal, to_free_highmem;
unsigned long save, to_free_normal, to_free_highmem;
to_free_normal = alloc_normal - count_data_pages();
save_highmem = count_highmem_pages();
if (alloc_highmem > save_highmem) {
to_free_highmem = alloc_highmem - save_highmem;
save = count_data_pages();
if (alloc_normal >= save) {
to_free_normal = alloc_normal - save;
save = 0;
} else {
to_free_normal = 0;
save -= alloc_normal;
}
save += count_highmem_pages();
if (alloc_highmem >= save) {
to_free_highmem = alloc_highmem - save;
} else {
to_free_highmem = 0;
to_free_normal -= save_highmem - alloc_highmem;
to_free_normal -= save - alloc_highmem;
}
memory_bm_position_reset(&copy_bm);
......@@ -1259,7 +1276,7 @@ int hibernate_preallocate_memory(void)
{
struct zone *zone;
unsigned long saveable, size, max_size, count, highmem, pages = 0;
unsigned long alloc, save_highmem, pages_highmem;
unsigned long alloc, save_highmem, pages_highmem, avail_normal;
struct timeval start, stop;
int error;
......@@ -1296,6 +1313,7 @@ int hibernate_preallocate_memory(void)
else
count += zone_page_state(zone, NR_FREE_PAGES);
}
avail_normal = count;
count += highmem;
count -= totalreserve_pages;
......@@ -1310,12 +1328,21 @@ int hibernate_preallocate_memory(void)
*/
if (size >= saveable) {
pages = preallocate_image_highmem(save_highmem);
pages += preallocate_image_memory(saveable - pages);
pages += preallocate_image_memory(saveable - pages, avail_normal);
goto out;
}
/* Estimate the minimum size of the image. */
pages = minimum_image_size(saveable);
/*
* To avoid excessive pressure on the normal zone, leave room in it to
* accommodate an image of the minimum size (unless it's already too
* small, in which case don't preallocate pages from it at all).
*/
if (avail_normal > pages)
avail_normal -= pages;
else
avail_normal = 0;
if (size < pages)
size = min_t(unsigned long, pages, max_size);
......@@ -1336,16 +1363,34 @@ int hibernate_preallocate_memory(void)
*/
pages_highmem = preallocate_image_highmem(highmem / 2);
alloc = (count - max_size) - pages_highmem;
pages = preallocate_image_memory(alloc);
if (pages < alloc)
goto err_out;
size = max_size - size;
alloc = size;
size = preallocate_highmem_fraction(size, highmem, count);
pages_highmem += size;
alloc -= size;
pages += preallocate_image_memory(alloc);
pages += pages_highmem;
pages = preallocate_image_memory(alloc, avail_normal);
if (pages < alloc) {
/* We have exhausted non-highmem pages, try highmem. */
alloc -= pages;
pages += pages_highmem;
pages_highmem = preallocate_image_highmem(alloc);
if (pages_highmem < alloc)
goto err_out;
pages += pages_highmem;
/*
* size is the desired number of saveable pages to leave in
* memory, so try to preallocate (all memory - size) pages.
*/
alloc = (count - pages) - size;
pages += preallocate_image_highmem(alloc);
} else {
/*
* There are approximately max_size saveable pages at this point
* and we want to reduce this number down to size.
*/
alloc = max_size - size;
size = preallocate_highmem_fraction(alloc, highmem, count);
pages_highmem += size;
alloc -= size;
size = preallocate_image_memory(alloc, avail_normal);
pages_highmem += preallocate_image_highmem(alloc - size);
pages += pages_highmem + size;
}
/*
* We only need as many page frames for the image as there are saveable
......
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