My knowledge of this is somewhat limited, however, since vmalloc already supported __GFP_NOFAIL in commit 9376130c390a ("mm/vmalloc: add support for __GFP_NOFAIL"). __GFP_NOFAIL could trigger the following stack and allocate high-order pages when CONFIG_HAVE_ARCH_HUGE_VMALLOC is enabled: __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5549 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2286 vm_area_alloc_pages mm/vmalloc.c:2989 [inline] __vmalloc_area_node mm/vmalloc.c:3057 [inline] __vmalloc_node_range+0x978/0x13c0 mm/vmalloc.c:3227 kvmalloc_node+0x156/0x1a0 mm/util.c:606 kvmalloc include/linux/slab.h:737 [inline] kvmalloc_array include/linux/slab.h:755 [inline] kvcalloc include/linux/slab.h:760 [inline] (codebase: Linux 6.2-rc2) Don't warn such cases since high-order pages with __GFP_NOFAIL is somewhat legel. Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 0745aedebb37..0618716c49df 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3822,12 +3822,6 @@ struct page *rmqueue(struct zone *preferred_zone, { struct page *page; - /* - * We most definitely don't want callers attempting to - * allocate greater than order-1 page units with __GFP_NOFAIL. - */ - WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1)); - if (likely(pcp_allowed_order(order))) { /* * MIGRATE_MOVABLE pcplist could have the pages on CMA area and -- 2.24.4