From 3800d55250976b7a4bd42c255b267bc242669709 Mon Sep 17 00:00:00 2001 From: Zi Yan Date: Wed, 4 Jun 2025 17:14:27 -0400 Subject: [PATCH] mm: rename CONFIG_PAGE_BLOCK_ORDER to CONFIG_PAGE_BLOCK_MAX_ORDER The config is in fact an additional upper limit of pageblock_order, so rename it to avoid confusion. Link: https://lkml.kernel.org/r/20250604211427.1590859-1-ziy@nvidia.com Signed-off-by: Zi Yan Acked-by: David Hildenbrand Reviewed-by: Oscar Salvador Acked-by: Juan Yescas Reviewed-by: Anshuman Khandual Acked-by: Vlastimil Babka Cc: "Isaac J. Manjarres" Cc: Kalesh Singh Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Masahiro Yamada Cc: Michal Hocko Cc: Mike Rapoport Cc: Minchan Kim Cc: Suren Baghdasaryan Cc: T.J. Mercier Signed-off-by: Andrew Morton --- include/linux/mmzone.h | 14 +++++++------- include/linux/pageblock-flags.h | 8 ++++---- mm/Kconfig | 15 ++++++++------- mm/mm_init.c | 2 +- 4 files changed, 20 insertions(+), 19 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 283913d42d7b3..5bec8b1d0e665 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -38,19 +38,19 @@ #define NR_PAGE_ORDERS (MAX_PAGE_ORDER + 1) /* Defines the order for the number of pages that have a migrate type. */ -#ifndef CONFIG_PAGE_BLOCK_ORDER -#define PAGE_BLOCK_ORDER MAX_PAGE_ORDER +#ifndef CONFIG_PAGE_BLOCK_MAX_ORDER +#define PAGE_BLOCK_MAX_ORDER MAX_PAGE_ORDER #else -#define PAGE_BLOCK_ORDER CONFIG_PAGE_BLOCK_ORDER -#endif /* CONFIG_PAGE_BLOCK_ORDER */ +#define PAGE_BLOCK_MAX_ORDER CONFIG_PAGE_BLOCK_MAX_ORDER +#endif /* CONFIG_PAGE_BLOCK_MAX_ORDER */ /* * The MAX_PAGE_ORDER, which defines the max order of pages to be allocated - * by the buddy allocator, has to be larger or equal to the PAGE_BLOCK_ORDER, + * by the buddy allocator, has to be larger or equal to the PAGE_BLOCK_MAX_ORDER, * which defines the order for the number of pages that can have a migrate type */ -#if (PAGE_BLOCK_ORDER > MAX_PAGE_ORDER) -#error MAX_PAGE_ORDER must be >= PAGE_BLOCK_ORDER +#if (PAGE_BLOCK_MAX_ORDER > MAX_PAGE_ORDER) +#error MAX_PAGE_ORDER must be >= PAGE_BLOCK_MAX_ORDER #endif /* diff --git a/include/linux/pageblock-flags.h b/include/linux/pageblock-flags.h index e73a4292ef02e..6297c6343c553 100644 --- a/include/linux/pageblock-flags.h +++ b/include/linux/pageblock-flags.h @@ -41,18 +41,18 @@ extern unsigned int pageblock_order; * Huge pages are a constant size, but don't exceed the maximum allocation * granularity. */ -#define pageblock_order MIN_T(unsigned int, HUGETLB_PAGE_ORDER, PAGE_BLOCK_ORDER) +#define pageblock_order MIN_T(unsigned int, HUGETLB_PAGE_ORDER, PAGE_BLOCK_MAX_ORDER) #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ #elif defined(CONFIG_TRANSPARENT_HUGEPAGE) -#define pageblock_order MIN_T(unsigned int, HPAGE_PMD_ORDER, PAGE_BLOCK_ORDER) +#define pageblock_order MIN_T(unsigned int, HPAGE_PMD_ORDER, PAGE_BLOCK_MAX_ORDER) #else /* CONFIG_TRANSPARENT_HUGEPAGE */ -/* If huge pages are not used, group by PAGE_BLOCK_ORDER */ -#define pageblock_order PAGE_BLOCK_ORDER +/* If huge pages are not used, group by PAGE_BLOCK_MAX_ORDER */ +#define pageblock_order PAGE_BLOCK_MAX_ORDER #endif /* CONFIG_HUGETLB_PAGE */ diff --git a/mm/Kconfig b/mm/Kconfig index 15716b1a5e21c..3b2060a61c05d 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -1005,8 +1005,8 @@ config ARCH_FORCE_MAX_ORDER # the default page block order is MAX_PAGE_ORDER (10) as per # include/linux/mmzone.h. # -config PAGE_BLOCK_ORDER - int "Page Block Order" +config PAGE_BLOCK_MAX_ORDER + int "Page Block Order Upper Limit" range 1 10 if ARCH_FORCE_MAX_ORDER = 0 default 10 if ARCH_FORCE_MAX_ORDER = 0 range 1 ARCH_FORCE_MAX_ORDER if ARCH_FORCE_MAX_ORDER != 0 @@ -1014,12 +1014,13 @@ config PAGE_BLOCK_ORDER help The page block order refers to the power of two number of pages that are physically contiguous and can have a migrate type associated to - them. The maximum size of the page block order is limited by - ARCH_FORCE_MAX_ORDER. + them. The maximum size of the page block order is at least limited by + ARCH_FORCE_MAX_ORDER/MAX_PAGE_ORDER. - This config allows overriding the default page block order when the - page block order is required to be smaller than ARCH_FORCE_MAX_ORDER - or MAX_PAGE_ORDER. + This config adds a new upper limit of default page block + order when the page block order is required to be smaller than + ARCH_FORCE_MAX_ORDER/MAX_PAGE_ORDER or other limits + (see include/linux/pageblock-flags.h for details). Reducing pageblock order can negatively impact THP generation success rate. If your workloads use THP heavily, please use this diff --git a/mm/mm_init.c b/mm/mm_init.c index f2944748f526d..02f41e2bdf60f 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -1509,7 +1509,7 @@ static inline void setup_usemap(struct zone *zone) {} /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ void __init set_pageblock_order(void) { - unsigned int order = PAGE_BLOCK_ORDER; + unsigned int order = PAGE_BLOCK_MAX_ORDER; /* Check that pageblock_nr_pages has not already been setup */ if (pageblock_order) -- 2.47.2