On 29.08.25 02:33, Liam R. Howlett wrote:
- David Hildenbrand david@redhat.com [250827 18:04]:
Let's reject them early, which in turn makes folio_alloc_gigantic() reject them properly.
To avoid converting from order to nr_pages, let's just add MAX_FOLIO_ORDER and calculate MAX_FOLIO_NR_PAGES based on that.
Reviewed-by: Zi Yan ziy@nvidia.com Acked-by: SeongJae Park sj@kernel.org Signed-off-by: David Hildenbrand david@redhat.com
Nit below, but..
Reviewed-by: Liam R. Howlett Liam.Howlett@oracle.com
include/linux/mm.h | 6 ++++-- mm/page_alloc.c | 5 ++++- 2 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h index 00c8a54127d37..77737cbf2216a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2055,11 +2055,13 @@ static inline long folio_nr_pages(const struct folio *folio) /* Only hugetlbfs can allocate folios larger than MAX_ORDER */ #ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE -#define MAX_FOLIO_NR_PAGES (1UL << PUD_ORDER) +#define MAX_FOLIO_ORDER PUD_ORDER #else -#define MAX_FOLIO_NR_PAGES MAX_ORDER_NR_PAGES +#define MAX_FOLIO_ORDER MAX_PAGE_ORDER #endif +#define MAX_FOLIO_NR_PAGES (1UL << MAX_FOLIO_ORDER)
- /*
- compound_nr() returns the number of pages in this potentially compound
- page. compound_nr() can be called on a tail page, and is defined to
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index baead29b3e67b..426bc404b80cc 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6833,6 +6833,7 @@ static int __alloc_contig_verify_gfp_mask(gfp_t gfp_mask, gfp_t *gfp_cc_mask) int alloc_contig_range_noprof(unsigned long start, unsigned long end, acr_flags_t alloc_flags, gfp_t gfp_mask) {
- const unsigned int order = ilog2(end - start); unsigned long outer_start, outer_end; int ret = 0;
@@ -6850,6 +6851,9 @@ int alloc_contig_range_noprof(unsigned long start, unsigned long end, PB_ISOLATE_MODE_CMA_ALLOC : PB_ISOLATE_MODE_OTHER;
- if (WARN_ON_ONCE((gfp_mask & __GFP_COMP) && order > MAX_FOLIO_ORDER))
return -EINVAL;- gfp_mask = current_gfp_context(gfp_mask); if (__alloc_contig_verify_gfp_mask(gfp_mask, (gfp_t *)&cc.gfp_mask)) return -EINVAL;
@@ -6947,7 +6951,6 @@ int alloc_contig_range_noprof(unsigned long start, unsigned long end, free_contig_range(end, outer_end - end); } else if (start == outer_start && end == outer_end && is_power_of_2(end - start)) { struct page *head = pfn_to_page(start);
int order = ilog2(end - start);You have changed this from an int to a const unsigned int, which is totally fine but it was left out of the change log.
Considered to trivial to document, but I can add a sentence about that.
Probably not really worth mentioning but curious why the change to unsigned here?
orders are always unsigned, like folio_order().
Thanks!