From: Zi Yan <z...@nvidia.com>
To test 1GB THP implemented in the following patches, this patch enables
changing MAX_ORDER of the buddy allocator.
It should be dropped later when we solely rely on mem_defrag to generate
1GB THPs.
Signed-off-by: Zi Yan <z...@nvidia.com>
---
arch/x86/Kconfig | 15 +++++++++++++++
arch/x86/include/asm/sparsemem.h | 4 ++--
2 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 68261430fe6e..f766ff5651d5 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1665,6 +1665,21 @@ config X86_PMEM_LEGACY
Say Y if unsure.
+config FORCE_MAX_ZONEORDER
+ int "Maximum zone order"
+ range 11 20
+ default "11"
+ 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.
+
+ This config option is actually maximum order plus one. For example,
+ a value of 11 means that the largest free memory block is 2^10 pages.
+
config HIGHPTE
bool "Allocate 3rd-level pagetables from highmem"
depends on HIGHMEM
diff --git a/arch/x86/include/asm/sparsemem.h b/arch/x86/include/asm/sparsemem.h
index 199218719a86..2df61d5ccc2d 100644
--- a/arch/x86/include/asm/sparsemem.h
+++ b/arch/x86/include/asm/sparsemem.h
@@ -21,12 +21,12 @@
# define MAX_PHYSADDR_BITS 36
# define MAX_PHYSMEM_BITS 36
# else
-# define SECTION_SIZE_BITS 26
+# define SECTION_SIZE_BITS 31
# define MAX_PHYSADDR_BITS 32
# define MAX_PHYSMEM_BITS 32
# endif
#else /* CONFIG_X86_32 */
-# define SECTION_SIZE_BITS 27 /* matt - 128 is convenient right now */
+# define SECTION_SIZE_BITS 31 /* matt - 128 is convenient right now */
# define MAX_PHYSADDR_BITS (pgtable_l5_enabled() ? 52 : 44)
# define MAX_PHYSMEM_BITS (pgtable_l5_enabled() ? 52 : 46)
#endif
--
2.20.1
