From 75558ad315488d40a18cb2c230ccacee24d20526 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Wed, 15 Mar 2023 14:31:24 +0300 Subject: sparc/mm: fix MAX_ORDER usage in tsb_grow() Patch series "Fix confusion around MAX_ORDER". MAX_ORDER currently defined as number of orders page allocator supports: user can ask buddy allocator for page order between 0 and MAX_ORDER-1. This definition is counter-intuitive and lead to number of bugs all over the kernel. Fix the bugs and then change the definition of MAX_ORDER to be inclusive: the range of orders user can ask from buddy allocator is 0..MAX_ORDER now. This patch (of 10): MAX_ORDER is not inclusive: the maximum allocation order buddy allocator can deliver is MAX_ORDER-1. Fix MAX_ORDER usage in tsb_grow(). Link: https://lkml.kernel.org/r/20230315113133.11326-1-kirill.shutemov@linux.intel.com Link: https://lkml.kernel.org/r/20230315113133.11326-2-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Reviewed-by: Mike Kravetz Acked-by: Mike Rapoport (IBM) Cc: David Miller Cc: David Hildenbrand Cc: Kirill A. Shutemov Cc: Mel Gorman Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- arch/sparc/mm/tsb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/sparc/mm/tsb.c') diff --git a/arch/sparc/mm/tsb.c b/arch/sparc/mm/tsb.c index 912205787161..dba8dffe2113 100644 --- a/arch/sparc/mm/tsb.c +++ b/arch/sparc/mm/tsb.c @@ -402,8 +402,8 @@ void tsb_grow(struct mm_struct *mm, unsigned long tsb_index, unsigned long rss) unsigned long new_rss_limit; gfp_t gfp_flags; - if (max_tsb_size > (PAGE_SIZE << MAX_ORDER)) - max_tsb_size = (PAGE_SIZE << MAX_ORDER); + if (max_tsb_size > (PAGE_SIZE << (MAX_ORDER - 1))) + max_tsb_size = (PAGE_SIZE << (MAX_ORDER - 1)); new_cache_index = 0; for (new_size = 8192; new_size < max_tsb_size; new_size <<= 1UL) { -- cgit