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Commit a664b2d8 authored by Andrea Arcangeli's avatar Andrea Arcangeli Committed by Linus Torvalds
Browse files

thp: madvise(MADV_NOHUGEPAGE) 



Add madvise MADV_NOHUGEPAGE to mark regions that are not important to be
hugepage backed.  Return -EINVAL if the vma is not of an anonymous type,
or the feature isn't built into the kernel.  Never silently return
success.

Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 1ddd6db4

include/linux/huge_mm.h

+8 −6
Original line number Diff line number Diff line
@@ -52,10 +52,12 @@ extern pmd_t *page_check_address_pmd(struct page *page, 
#define HPAGE_PMD_SIZE HPAGE_SIZE



#define transparent_hugepage_enabled(__vma)				\

	(transparent_hugepage_flags & (1<<TRANSPARENT_HUGEPAGE_FLAG) ||	\

	((transparent_hugepage_flags &					\

	  (1<<TRANSPARENT_HUGEPAGE_FLAG) ||				\

	  (transparent_hugepage_flags &					\

	   (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG) &&			\

	  (__vma)->vm_flags & VM_HUGEPAGE))

	   ((__vma)->vm_flags & VM_HUGEPAGE))) &&			\

	 !((__vma)->vm_flags & VM_NOHUGEPAGE))

#define transparent_hugepage_defrag(__vma)				\

	((transparent_hugepage_flags &					\

	  (1<<TRANSPARENT_HUGEPAGE_DEFRAG_FLAG)) ||			\
@@ -103,7 +105,7 @@ extern void __split_huge_page_pmd(struct mm_struct *mm, pmd_t *pmd); 
#if HPAGE_PMD_ORDER > MAX_ORDER

#error "hugepages can't be allocated by the buddy allocator"

#endif

extern int hugepage_madvise(unsigned long *vm_flags);

extern int hugepage_madvise(unsigned long *vm_flags, int advice);

extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,

				    unsigned long start,

				    unsigned long end,
@@ -141,7 +143,7 @@ static inline int split_huge_page(struct page *page) 
	do { } while (0)

#define wait_split_huge_page(__anon_vma, __pmd)	\

	do { } while (0)

static inline int hugepage_madvise(unsigned long *vm_flags)

static inline int hugepage_madvise(unsigned long *vm_flags, int advice)

{

	BUG();

	return 0;

include/linux/khugepaged.h

+4 −3
Original line number Diff line number Diff line
@@ -38,9 +38,10 @@ static inline void khugepaged_exit(struct mm_struct *mm) 
static inline int khugepaged_enter(struct vm_area_struct *vma)

{

	if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags))

		if (khugepaged_always() ||

		if ((khugepaged_always() ||

		     (khugepaged_req_madv() &&

		     vma->vm_flags & VM_HUGEPAGE))

		      vma->vm_flags & VM_HUGEPAGE)) &&

		    !(vma->vm_flags & VM_NOHUGEPAGE))

			if (__khugepaged_enter(vma->vm_mm))

				return -ENOMEM;

	return 0;

include/linux/mm.h

+1 −0
Original line number Diff line number Diff line
@@ -83,6 +83,7 @@ extern unsigned int kobjsize(const void *objp); 
#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.. */

mm/huge_memory.c

+30 −11
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/kthread.h>

#include <linux/khugepaged.h>

#include <linux/freezer.h>

#include <linux/mman.h>

#include <asm/tlb.h>

#include <asm/pgalloc.h>

#include "internal.h"
@@ -1388,18 +1389,36 @@ int split_huge_page(struct page *page) 
	return ret;

}



int hugepage_madvise(unsigned long *vm_flags)

int hugepage_madvise(unsigned long *vm_flags, int advice)

{

	switch (advice) {

	case MADV_HUGEPAGE:

		/*

		 * Be somewhat over-protective like KSM for now!

		 */

	if (*vm_flags & (VM_HUGEPAGE | VM_SHARED  | VM_MAYSHARE   |

		if (*vm_flags & (VM_HUGEPAGE |

				 VM_SHARED   | VM_MAYSHARE   |

				 VM_PFNMAP   | VM_IO      | VM_DONTEXPAND |

				 VM_RESERVED | VM_HUGETLB | VM_INSERTPAGE |

				 VM_MIXEDMAP | VM_SAO))

			return -EINVAL;



		*vm_flags &= ~VM_NOHUGEPAGE;

		*vm_flags |= VM_HUGEPAGE;

		break;

	case MADV_NOHUGEPAGE:

		/*

		 * Be somewhat over-protective like KSM for now!

		 */

		if (*vm_flags & (VM_NOHUGEPAGE |

				 VM_SHARED   | VM_MAYSHARE   |

				 VM_PFNMAP   | VM_IO      | VM_DONTEXPAND |

				 VM_RESERVED | VM_HUGETLB | VM_INSERTPAGE |

				 VM_MIXEDMAP | VM_SAO))

			return -EINVAL;

		*vm_flags &= ~VM_HUGEPAGE;

		*vm_flags |= VM_NOHUGEPAGE;

		break;

	}



	return 0;

}

mm/madvise.c

+3 −1
Original line number Diff line number Diff line
@@ -72,7 +72,8 @@ static long madvise_behavior(struct vm_area_struct * vma, 
			goto out;

		break;

	case MADV_HUGEPAGE:

		error = hugepage_madvise(&new_flags);

	case MADV_NOHUGEPAGE:

		error = hugepage_madvise(&new_flags, behavior);

		if (error)

			goto out;

		break;
@@ -290,6 +291,7 @@ madvise_behavior_valid(int behavior) 
#endif

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

	case MADV_HUGEPAGE:

	case MADV_NOHUGEPAGE:

#endif

		return 1;