Re: [PATCH v3 02/14] arm64: drop ranges in definition of ARCH_FORCE_MAX_ORDER

From: Kefeng Wang
Date: Sat Mar 25 2023 - 02:35:28 EST




On 2023/3/25 14:08, Mike Rapoport wrote:
From: "Mike Rapoport (IBM)" <rppt@xxxxxxxxxx>

It is not a good idea to change fundamental parameters of core memory
management. Having predefined ranges suggests that the values within
those ranges are sensible, but one has to *really* understand
implications of changing MAX_ORDER before actually amending it and
ranges don't help here.

Drop ranges in definition of ARCH_FORCE_MAX_ORDER and make its prompt
visible only if EXPERT=y

Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>

Reviewed-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>

---
arch/arm64/Kconfig | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index e60baf7859d1..7324032af859 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1487,11 +1487,9 @@ config XEN
# 16K | 27 | 14 | 13 | 11 |
# 64K | 29 | 16 | 13 | 13 |
config ARCH_FORCE_MAX_ORDER
- int "Maximum zone order" if ARM64_4K_PAGES || ARM64_16K_PAGES
+ int "Maximum zone order" if EXPERT && (ARM64_4K_PAGES || ARM64_16K_PAGES)
default "13" if ARM64_64K_PAGES
- range 11 13 if ARM64_16K_PAGES
default "11" if ARM64_16K_PAGES
- range 10 15 if ARM64_4K_PAGES
default "10"
help
The kernel memory allocator divides physically contiguous memory