| Message ID | 20221104054119.1946073-3-tgsp002@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | Fixes to the hibernate_preallocate_memory() | expand |
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; > } > > /*
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; >> } >> /* >
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; } /*