On Wednesday 05 April 2017 11:05 AM, Anshuman Khandual wrote:
On 04/04/2017 07:33 PM, Aneesh Kumar K.V wrote:
This patch adds support for gigantic pages in ppc64. We also updates
gigantic_page_supported helper such that arch can override it.
Seems like only radix based 1GB is considered as gigantic page in this
implementation. What about the existing 16GB pages support ? IIUC they
are still supported currently as gigantic pages (as defined in generic
HugeTLB) if the platform gives us reserved memory areas during boot.
Can you explain how this is going to be different ?
Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/book3s/64/hugetlb.h | 9 +++++++++
arch/powerpc/mm/hugetlbpage.c | 7 +++++--
arch/powerpc/platforms/Kconfig.cputype | 1 +
mm/hugetlb.c | 4 ++++
4 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h
b/arch/powerpc/include/asm/book3s/64/hugetlb.h
index 6666cd366596..a994d069fdaf 100644
--- a/arch/powerpc/include/asm/book3s/64/hugetlb.h
+++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h
@@ -50,4 +50,13 @@ static inline pte_t arch_make_huge_pte(pte_t entry, struct
vm_area_struct *vma,
else
return entry;
}
+
+#define gigantic_page_supported gigantic_page_supported
+static inline bool gigantic_page_supported(void)
+{
+ if (radix_enabled())
+ return true;
+ return false;
+}
POWER8 (non radix MMU) cannot have 16GB gigantic HugeTLB pages ?
that helper determines whether we can do gigantic page allocation at
runtime. I doubt we can do that for 16GB pages. Hence this is only
enabled for 1G radix config
-aneesh
