From cc2383ec06be093789469852e1fe96e1148e9a2c Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Mon, 8 Oct 2012 16:28:37 -0700 Subject: [PATCH] mm: introduce arch-specific vma flag VM_ARCH_1 Combine several arch-specific vma flags into one. before patch: 0x00000200 0x01000000 0x20000000 0x40000000 x86 VM_NOHUGEPAGE VM_HUGEPAGE - VM_PAT powerpc - - VM_SAO - parisc VM_GROWSUP - - - ia64 VM_GROWSUP - - - nommu - VM_MAPPED_COPY - - others - - - - after patch: 0x00000200 0x01000000 0x20000000 0x40000000 x86 - VM_PAT VM_HUGEPAGE VM_NOHUGEPAGE powerpc - VM_SAO - - parisc - VM_GROWSUP - - ia64 - VM_GROWSUP - - nommu - VM_MAPPED_COPY - - others - VM_ARCH_1 - - And voila! One completely free bit. Signed-off-by: Konstantin Khlebnikov Cc: Alexander Viro Cc: Carsten Otte Cc: Chris Metcalf Cc: Cyrill Gorcunov Cc: Eric Paris Cc: H. Peter Anvin Cc: Hugh Dickins Cc: Ingo Molnar Cc: James Morris Cc: Jason Baron Cc: Kentaro Takeda Cc: Matt Helsley Cc: Nick Piggin Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Robert Richter Cc: Suresh Siddha Cc: Tetsuo Handa Cc: Venkatesh Pallipadi Acked-by: Linus Torvalds Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mm.h | 34 +++++++++++++++++++++------------- mm/huge_memory.c | 2 +- mm/ksm.c | 7 ++++++- 3 files changed, 28 insertions(+), 15 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 75d1632..9c039f8 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -70,6 +70,8 @@ extern unsigned int kobjsize(const void *objp); /* * vm_flags in vm_area_struct, see mm_types.h. */ +#define VM_NONE 0x00000000 + #define VM_READ 0x00000001 /* currently active flags */ #define VM_WRITE 0x00000002 #define VM_EXEC 0x00000004 @@ -82,12 +84,6 @@ extern unsigned int kobjsize(const void *objp); #define VM_MAYSHARE 0x00000080 #define VM_GROWSDOWN 0x00000100 /* general info on the segment */ -#if defined(CONFIG_STACK_GROWSUP) || defined(CONFIG_IA64) -#define VM_GROWSUP 0x00000200 -#else -#define VM_GROWSUP 0x00000000 -#define VM_NOHUGEPAGE 0x00000200 /* MADV_NOHUGEPAGE marked this vma */ -#endif #define VM_PFNMAP 0x00000400 /* Page-ranges managed without "struct page", just pure PFN */ #define VM_DENYWRITE 0x00000800 /* ETXTBSY on write attempts.. */ @@ -106,20 +102,32 @@ extern unsigned int kobjsize(const void *objp); #define VM_NORESERVE 0x00200000 /* should the VM suppress accounting */ #define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */ #define VM_NONLINEAR 0x00800000 /* Is non-linear (remap_file_pages) */ -#ifndef CONFIG_TRANSPARENT_HUGEPAGE -#define VM_MAPPED_COPY 0x01000000 /* T if mapped copy of data (nommu mmap) */ -#else -#define VM_HUGEPAGE 0x01000000 /* MADV_HUGEPAGE marked this vma */ -#endif +#define VM_ARCH_1 0x01000000 /* Architecture-specific flag */ #define VM_INSERTPAGE 0x02000000 /* The vma has had "vm_insert_page()" done on it */ #define VM_NODUMP 0x04000000 /* Do not include in the core dump */ #define VM_CAN_NONLINEAR 0x08000000 /* Has ->fault & does nonlinear pages */ #define VM_MIXEDMAP 0x10000000 /* Can contain "struct page" and pure PFN pages */ -#define VM_SAO 0x20000000 /* Strong Access Ordering (powerpc) */ -#define VM_PAT 0x40000000 /* PAT reserves whole VMA at once (x86) */ +#define VM_HUGEPAGE 0x20000000 /* MADV_HUGEPAGE marked this vma */ +#define VM_NOHUGEPAGE 0x40000000 /* MADV_NOHUGEPAGE marked this vma */ #define VM_MERGEABLE 0x80000000 /* KSM may merge identical pages */ +#if defined(CONFIG_X86) +# define VM_PAT VM_ARCH_1 /* PAT reserves whole VMA at once (x86) */ +#elif defined(CONFIG_PPC) +# define VM_SAO VM_ARCH_1 /* Strong Access Ordering (powerpc) */ +#elif defined(CONFIG_PARISC) +# define VM_GROWSUP VM_ARCH_1 +#elif defined(CONFIG_IA64) +# define VM_GROWSUP VM_ARCH_1 +#elif !defined(CONFIG_MMU) +# define VM_MAPPED_COPY VM_ARCH_1 /* T if mapped copy of data (nommu mmap) */ +#endif + +#ifndef VM_GROWSUP +# define VM_GROWSUP VM_NONE +#endif + /* Bits set in the VMA until the stack is in its final location */ #define VM_STACK_INCOMPLETE_SETUP (VM_RAND_READ | VM_SEQ_READ) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 73cb22e..4720669 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1491,7 +1491,7 @@ out: return ret; } -#define VM_NO_THP (VM_SPECIAL|VM_INSERTPAGE|VM_MIXEDMAP|VM_SAO| \ +#define VM_NO_THP (VM_SPECIAL|VM_INSERTPAGE|VM_MIXEDMAP| \ VM_HUGETLB|VM_SHARED|VM_MAYSHARE) int hugepage_madvise(struct vm_area_struct *vma, diff --git a/mm/ksm.c b/mm/ksm.c index 47c8853..d1cbe2a 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -1470,9 +1470,14 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start, if (*vm_flags & (VM_MERGEABLE | VM_SHARED | VM_MAYSHARE | VM_PFNMAP | VM_IO | VM_DONTEXPAND | VM_RESERVED | VM_HUGETLB | VM_INSERTPAGE | - VM_NONLINEAR | VM_MIXEDMAP | VM_SAO)) + VM_NONLINEAR | VM_MIXEDMAP)) return 0; /* just ignore the advice */ +#ifdef VM_SAO + if (*vm_flags & VM_SAO) + return 0; +#endif + if (!test_bit(MMF_VM_MERGEABLE, &mm->flags)) { err = __ksm_enter(mm); if (err) -- 2.7.4