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;
+
/*
* There are approximately max_size saveable pages at this point
* and we want to reduce this number down to size.
@@ -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;
}
/*
--
2.25.1On 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;
> }
>
> /*
--
js
suse labs
在 2022/11/4 14:25, Jiri Slaby 写道:
> 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?
If there is no need to make judgments here, then in the (pages < alloc)
branch, it is necessary to make judgments on (pages_highmem < alloc)?
should be the same;
>
>> @@ -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;
>> }
>> /*
>
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