On 04. 11. 22, 6:41, TGSP wrote:
From: xiongxin xiongxin@kylinos.cn
Added a check on the return value of preallocate_image_highmem(). If memory preallocate is insufficient, S4 cannot be done;
I am playing 4K video on a machine with AMD or other graphics card and only 8GiB memory, and the kernel is not configured with CONFIG_HIGHMEM. When doing the S4 test, the analysis found that when the pages get from minimum_image_size() is large enough, The preallocate_image_memory() and preallocate_image_highmem() calls failed to obtain enough memory. Add the judgment that memory preallocate is insufficient;
The detailed debugging data is as follows:
image_size: 3225923584, totalram_pages: 1968948 in hibernate_reserved_size_init();
in hibernate_preallocate_memory(): code pages = minimum_image_size(saveable) = 717992, at this time(line): count: 2030858 avail_normal: 2053753 highmem: 0 totalreserve_pages: 22895 max_size: 1013336 size: 787579 saveable: 1819905
When the code executes to: pages = preallocate_image_memory(alloc, avail_normal), at that time(line): pages_highmem: 0 avail_normal: 1335761 alloc: 1017522 pages: 1017522
So enter the else branch judged by (pages < alloc), When executed to size = preallocate_image_memory(alloc, avail_normal): alloc = max_size - size = 225757; size = preallocate_image_memory(alloc, avail_normal) = 168671, That is, preallocate_image_memory() does not apply for all alloc memory pages, because highmem is not enabled, and size_highmem will return 0 here, so there is a memory page that has not been preallocated, so I think a judgment needs to be added here.
But what I can't understand is that although pages are not preallocated enough, "pages -= free_unnecessary_pages()" in the code below can also discard some pages that have been preallocated, so I am not sure whether it is appropriate to add a judgment here.
Cc: stable@vger.kernel.org Signed-off-by: xiongxin xiongxin@kylinos.cn Signed-off-by: huanglei huanglei@kylinos.cn
kernel/power/snapshot.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index c20ca5fb9adc..546d544cf7de 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -1854,6 +1854,8 @@ int hibernate_preallocate_memory(void) alloc = (count - pages) - size; pages += preallocate_image_highmem(alloc); } else {
unsigned long size_highmem = 0;
This needs not be initialized, right?
@@ -1863,8 +1865,13 @@ int hibernate_preallocate_memory(void) pages_highmem += size; alloc -= size; size = preallocate_image_memory(alloc, avail_normal);
pages_highmem += preallocate_image_highmem(alloc - size);pages += pages_highmem + size;
size_highmem = preallocate_image_highmem(alloc - size);if (size_highmem < (alloc - size)) {pr_err("Image allocation is %lu pages short, exit\n",alloc - size - pages_highmem);goto err_out;}pages += pages_highmem + size_highmem + size;/*