From 6fc54303aa2597e30558cdbd310d45070c9a0325 Mon Sep 17 00:00:00 2001 From: "Mike Rapoport (IBM)" Date: Fri, 24 Mar 2023 08:22:28 +0300 Subject: [PATCH] powerpc: reword ARCH_FORCE_MAX_ORDER prompt and help text The prompt and help text of ARCH_FORCE_MAX_ORDER are not even close to describe this configuration option. Update both to actually describe what this option does. Link: https://lkml.kernel.org/r/20230324052233.2654090-10-rppt@kernel.org Signed-off-by: Mike Rapoport (IBM) Acked-by: Kirill A. Shutemov Reviewed-by: Zi Yan Cc: Arnd Bergmann Cc: Catalin Marinas Cc: Christophe Leroy Cc: David Miller Cc: Dinh Nguyen Cc: Geert Uytterhoeven Cc: Guo Ren Cc: John Paul Adrian Glaubitz Cc: Max Filippov Cc: Michael Ellerman Cc: Rich Felker Cc: "Russell King (Oracle)" Cc: Will Deacon Cc: Yoshinori Sato Signed-off-by: Andrew Morton --- arch/powerpc/Kconfig | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 24d56536b269..c0095bf795ca 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -896,7 +896,7 @@ config DATA_SHIFT 8M pages will be pinned. config ARCH_FORCE_MAX_ORDER - int "Maximum zone order" + int "Order of maximal physically contiguous allocations" range 7 8 if PPC64 && PPC_64K_PAGES default "8" if PPC64 && PPC_64K_PAGES range 12 12 if PPC64 && !PPC_64K_PAGES @@ -910,17 +910,19 @@ config ARCH_FORCE_MAX_ORDER range 10 63 default "10" help - The kernel memory allocator divides physically contiguous memory - blocks into "zones", where each zone is a power of two number of - pages. This option selects the largest power of two that the kernel - keeps in the memory allocator. If you need to allocate very large - blocks of physically contiguous memory, then you may need to - increase this value. + The kernel page allocator limits the size of maximal physically + contiguous allocations. The limit is called MAX_ORDER and it + defines the maximal power of two of number of pages that can be + allocated as a single contiguous block. This option allows + overriding the default setting when ability to allocate very + large blocks of physically contiguous memory is required. The page size is not necessarily 4KB. For example, on 64-bit systems, 64KB pages can be enabled via CONFIG_PPC_64K_PAGES. Keep this in mind when choosing a value for this option. + Don't change if unsure. + config PPC_SUBPAGE_PROT bool "Support setting protections for 4k subpages (subpage_prot syscall)" default n