[PATCHv5 11/11] x86, mm: enable split page table lock for PMD level

Kirill A. Shutemov
2013-10-07T13:56:36Z

Enable PMD split page table lock for X86_64 and PAE.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Alex Thorlton <athorlton@sgi.com>
---
arch/x86/Kconfig | 4 ++++
arch/x86/include/asm/pgalloc.h | 11 ++++++++++-
2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index ee2fb9d377..015d1362b7 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1880,6 +1880,10 @@ config USE_PERCPU_NUMA_NODE_ID
def_bool y
depends on NUMA

+config ARCH_ENABLE_SPLIT_PMD_PTLOCK
+ def_bool y
+ depends on X86_64 || X86_PAE
+
menu "Power management and ACPI options"

config ARCH_HIBERNATION_HEADER
diff --git a/arch/x86/include/asm/pgalloc.h b/arch/x86/include/asm/pgalloc.h
index b4389a468f..e2fb2b6934 100644
--- a/arch/x86/include/asm/pgalloc.h
+++ b/arch/x86/include/asm/pgalloc.h
@@ -80,12 +80,21 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
#if PAGETABLE_LEVELS > 2
static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
{
- return (pmd_t *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
+ struct page *page;
+ page = alloc_pages(GFP_KERNEL | __GFP_REPEAT| __GFP_ZERO, 0);
+ if (!page)
+ return NULL;
+ if (!pgtable_pmd_page_ctor(page)) {
+ __free_pages(page, 0);
+ return NULL;
+ }
+ return (pmd_t *)page_address(page);
}

static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
{
BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
+ pgtable_pmd_page_dtor(virt_to_page(pmd));
free_page((unsigned long)pmd);
}

--
1.8.4.rc3