From 23baf831a32c04f9a968812511540b1b3e648bf5 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Wed, 15 Mar 2023 14:31:33 +0300 Subject: mm, treewide: redefine MAX_ORDER sanely 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. Change the definition of MAX_ORDER to be inclusive: the range of orders user can ask from buddy allocator is 0..MAX_ORDER now. [kirill@shutemov.name: fix min() warning] Link: https://lkml.kernel.org/r/20230315153800.32wib3n5rickolvh@box [akpm@linux-foundation.org: fix another min_t warning] [kirill@shutemov.name: fixups per Zi Yan] Link: https://lkml.kernel.org/r/20230316232144.b7ic4cif4kjiabws@box.shutemov.name [akpm@linux-foundation.org: fix underlining in docs] Link: https://lore.kernel.org/oe-kbuild-all/202303191025.VRCTk6mP-lkp@intel.com/ Link: https://lkml.kernel.org/r/20230315113133.11326-11-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Reviewed-by: Michael Ellerman [powerpc] Cc: "Kirill A. Shutemov" Cc: Zi Yan Signed-off-by: Andrew Morton --- mm/slub.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'mm/slub.c') diff --git a/mm/slub.c b/mm/slub.c index 32eb6b50fe18..f49d669ff604 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -4171,8 +4171,8 @@ static inline int calculate_order(unsigned int size) /* * Doh this slab cannot be placed using slub_max_order. */ - order = calc_slab_order(size, 1, MAX_ORDER - 1, 1); - if (order < MAX_ORDER) + order = calc_slab_order(size, 1, MAX_ORDER, 1); + if (order <= MAX_ORDER) return order; return -ENOSYS; } @@ -4697,7 +4697,7 @@ __setup("slub_min_order=", setup_slub_min_order); static int __init setup_slub_max_order(char *str) { get_option(&str, (int *)&slub_max_order); - slub_max_order = min(slub_max_order, (unsigned int)MAX_ORDER - 1); + slub_max_order = min_t(unsigned int, slub_max_order, MAX_ORDER); return 1; } -- cgit v1.2.3-70-g09d2