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authorMel Gorman <mgorman@suse.de>2014-10-10 02:26:33 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-10-10 06:25:52 +0400
commit6a33979d5bd7521497121c5ae4435d7003115a0f (patch)
treef010f2441b1942f0153b999fa987196e68a30272 /arch/x86
parented2f240094f900833ac06f533ab8bbcf0a1e8199 (diff)
downloadlinux-6a33979d5bd7521497121c5ae4435d7003115a0f.tar.xz
mm: remove misleading ARCH_USES_NUMA_PROT_NONE
ARCH_USES_NUMA_PROT_NONE was defined for architectures that implemented _PAGE_NUMA using _PROT_NONE. This saved using an additional PTE bit and relied on the fact that PROT_NONE vmas were skipped by the NUMA hinting fault scanner. This was found to be conceptually confusing with a lot of implicit assumptions and it was asked that an alternative be found. Commit c46a7c81 "x86: define _PAGE_NUMA by reusing software bits on the PMD and PTE levels" redefined _PAGE_NUMA on x86 to be one of the swap PTE bits and shrunk the maximum possible swap size but it did not go far enough. There are no architectures that reuse _PROT_NONE as _PROT_NUMA but the relics still exist. This patch removes ARCH_USES_NUMA_PROT_NONE and removes some unnecessary duplication in powerpc vs the generic implementation by defining the types the core NUMA helpers expected to exist from x86 with their ppc64 equivalent. This necessitated that a PTE bit mask be created that identified the bits that distinguish present from NUMA pte entries but it is expected this will only differ between arches based on _PAGE_PROTNONE. The naming for the generic helpers was taken from x86 originally but ppc64 has types that are equivalent for the purposes of the helper so they are mapped instead of duplicating code. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--arch/x86/include/asm/pgtable_types.h14
2 files changed, 14 insertions, 1 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index e4b1f431c7ed..3eb8a41509b3 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -30,7 +30,6 @@ config X86
select HAVE_UNSTABLE_SCHED_CLOCK
select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
select ARCH_SUPPORTS_INT128 if X86_64
- select ARCH_WANTS_PROT_NUMA_PROT_NONE
select HAVE_IDE
select HAVE_OPROFILE
select HAVE_PCSPKR_PLATFORM
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index f216963760e5..0f9724c9c510 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -325,6 +325,20 @@ static inline pteval_t pte_flags(pte_t pte)
return native_pte_val(pte) & PTE_FLAGS_MASK;
}
+#ifdef CONFIG_NUMA_BALANCING
+/* Set of bits that distinguishes present, prot_none and numa ptes */
+#define _PAGE_NUMA_MASK (_PAGE_NUMA|_PAGE_PROTNONE|_PAGE_PRESENT)
+static inline pteval_t ptenuma_flags(pte_t pte)
+{
+ return pte_flags(pte) & _PAGE_NUMA_MASK;
+}
+
+static inline pmdval_t pmdnuma_flags(pmd_t pmd)
+{
+ return pmd_flags(pmd) & _PAGE_NUMA_MASK;
+}
+#endif /* CONFIG_NUMA_BALANCING */
+
#define pgprot_val(x) ((x).pgprot)
#define __pgprot(x) ((pgprot_t) { (x) } )