On Tue, Nov 1, 2022 at 3:28 AM TGSP <tgsp002@xxxxxxxxx> wrote:
>
> From: xiongxin <xiongxin@xxxxxxxxxx>
>
> 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;
>
> "pages -= free_unnecessary_pages()" below will let pages to drop a lot,
> so I wonder if it makes sense to add a judgment here.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: xiongxin <xiongxin@xxxxxxxxxx>
> Signed-off-by: huanglei <huanglei@xxxxxxxxxx>
> ---
> kernel/power/snapshot.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
> index c20ca5fb9adc..670abf89cf31 100644
> --- a/kernel/power/snapshot.c
> +++ b/kernel/power/snapshot.c
> @@ -1738,6 +1738,7 @@ 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, avail_normal;
> + unsigned long size_highmem;
Please define this in the block where it will be used.
> ktime_t start, stop;
> int error;
>
> @@ -1863,7 +1864,13 @@ int hibernate_preallocate_memory(void)
> pages_highmem += size;
The line above can be dropped.
> alloc -= size;
> size = preallocate_image_memory(alloc, avail_normal);
> - pages_highmem += preallocate_image_highmem(alloc - size);
> + size_highmem += preallocate_image_highmem(alloc - size);
Did you mean "="?
Assuming you did, this could be
size_highmem = size + preallocate_image_highmem(alloc - size);
if (size_highmem < alloc) {
> + if (size_highmem < (alloc - size)) {
The inner parens were not necessary.
> + pr_err("Image allocation is %lu pages short, exit\n",
> + alloc - size - pages_highmem);
> + goto err_out;
> + }
> + pages_highmem += size_highmem;
> pages += pages_highmem + size;
> }
>
> --
But overall it would be better to avoid bailing out.
