| Message ID | 20250415111859.376302-1-osalvador@suse.de (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm, hugetlb: Increment the number of pages to be reset on HVO | expand |
On 15.04.25 13:18, Oscar Salvador wrote: > commit 4eeec8c89a0c ("mm: move hugetlb specific things in folio to page[3]") > shifted hugetlb specific stuff, and now mapping overlaps _hugetlb_cgroup field. > > Upon restoring the vmemmap for HVO, only the first two tail pages are reset, and > this causes the check in free_tail_page_prepare() to fail as it finds > an unexpected mapping value in some tails. > > Increment the number of pages to be reset to 4 (head + 3 tail pages) > > Fixes: 4eeec8c89a0c ("mm: move hugetlb specific things in folio to page[3]") > Suggested-by: David Hildenbrand <david@redhat.com> > Signed-off-by: Oscar Salvador <osalvador@suse.de> > --- > mm/hugetlb_vmemmap.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c > index 9a99dfa3c495..27245e86df25 100644 > --- a/mm/hugetlb_vmemmap.c > +++ b/mm/hugetlb_vmemmap.c > @@ -238,11 +238,11 @@ static void vmemmap_remap_pte(pte_t *pte, unsigned long addr, > * struct page, the special metadata (e.g. page->flags or page->mapping) > * cannot copy to the tail struct page structs. The invalid value will be > * checked in the free_tail_page_prepare(). In order to avoid the message > - * of "corrupted mapping in tail page". We need to reset at least 3 (one > - * head struct page struct and two tail struct page structs) struct page > + * of "corrupted mapping in tail page". We need to reset at least 4 (one > + * head struct page struct and three tail struct page structs) struct page > * structs. > */ > -#define NR_RESET_STRUCT_PAGE 3 > +#define NR_RESET_STRUCT_PAGE 4 > > static inline void reset_struct_pages(struct page *start) > { Thanks! Reviewed-by: David Hildenbrand <david@redhat.com>
> On Apr 15, 2025, at 19:18, Oscar Salvador <osalvador@suse.de> wrote: > > commit 4eeec8c89a0c ("mm: move hugetlb specific things in folio to page[3]") > shifted hugetlb specific stuff, and now mapping overlaps _hugetlb_cgroup field. > > Upon restoring the vmemmap for HVO, only the first two tail pages are reset, and > this causes the check in free_tail_page_prepare() to fail as it finds > an unexpected mapping value in some tails. > > Increment the number of pages to be reset to 4 (head + 3 tail pages) > > Fixes: 4eeec8c89a0c ("mm: move hugetlb specific things in folio to page[3]") > Suggested-by: David Hildenbrand <david@redhat.com> > Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Muchun Song <muchun.song@linux.dev> Thanks.
diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index 9a99dfa3c495..27245e86df25 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -238,11 +238,11 @@ static void vmemmap_remap_pte(pte_t *pte, unsigned long addr, * struct page, the special metadata (e.g. page->flags or page->mapping) * cannot copy to the tail struct page structs. The invalid value will be * checked in the free_tail_page_prepare(). In order to avoid the message - * of "corrupted mapping in tail page". We need to reset at least 3 (one - * head struct page struct and two tail struct page structs) struct page + * of "corrupted mapping in tail page". We need to reset at least 4 (one + * head struct page struct and three tail struct page structs) struct page * structs. */ -#define NR_RESET_STRUCT_PAGE 3 +#define NR_RESET_STRUCT_PAGE 4 static inline void reset_struct_pages(struct page *start) {
commit 4eeec8c89a0c ("mm: move hugetlb specific things in folio to page[3]") shifted hugetlb specific stuff, and now mapping overlaps _hugetlb_cgroup field. Upon restoring the vmemmap for HVO, only the first two tail pages are reset, and this causes the check in free_tail_page_prepare() to fail as it finds an unexpected mapping value in some tails. Increment the number of pages to be reset to 4 (head + 3 tail pages) Fixes: 4eeec8c89a0c ("mm: move hugetlb specific things in folio to page[3]") Suggested-by: David Hildenbrand <david@redhat.com> Signed-off-by: Oscar Salvador <osalvador@suse.de> --- mm/hugetlb_vmemmap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)