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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2016-07-27 01:26:21 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-07-27 02:19:19 +0300
commit657e3038c4e6fcd3cef41f2b01c655a685a7b8c7 (patch)
treead015c70c6a1befac182b9113ac4d27cf94dadb7 /mm
parent800d8c63b2e989c2e349632d1648119bf5862f01 (diff)
downloadlinux-657e3038c4e6fcd3cef41f2b01c655a685a7b8c7.tar.xz
shmem, thp: respect MADV_{NO,}HUGEPAGE for file mappings
Let's wire up existing madvise() hugepage hints for file mappings. MADV_HUGEPAGE advise shmem to allocate huge page on page fault in the VMA. It only has effect if the filesystem is mounted with huge=advise or huge=within_size. MADV_NOHUGEPAGE prevents hugepage from being allocated on page fault in the VMA. It doesn't prevent a huge page from being allocated by other means, i.e. page fault into different mapping or write(2) into file. Link: http://lkml.kernel.org/r/1466021202-61880-31-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/huge_memory.c19
-rw-r--r--mm/shmem.c20
2 files changed, 22 insertions, 17 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 0f58460cd69c..5eba97874ad5 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1830,7 +1830,7 @@ spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma)
return NULL;
}
-#define VM_NO_THP (VM_SPECIAL | VM_HUGETLB | VM_SHARED | VM_MAYSHARE)
+#define VM_NO_KHUGEPAGED (VM_SPECIAL | VM_HUGETLB | VM_SHARED | VM_MAYSHARE)
int hugepage_madvise(struct vm_area_struct *vma,
unsigned long *vm_flags, int advice)
@@ -1846,11 +1846,6 @@ int hugepage_madvise(struct vm_area_struct *vma,
if (mm_has_pgste(vma->vm_mm))
return 0;
#endif
- /*
- * Be somewhat over-protective like KSM for now!
- */
- if (*vm_flags & VM_NO_THP)
- return -EINVAL;
*vm_flags &= ~VM_NOHUGEPAGE;
*vm_flags |= VM_HUGEPAGE;
/*
@@ -1858,15 +1853,11 @@ int hugepage_madvise(struct vm_area_struct *vma,
* register it here without waiting a page fault that
* may not happen any time soon.
*/
- if (unlikely(khugepaged_enter_vma_merge(vma, *vm_flags)))
+ if (!(*vm_flags & VM_NO_KHUGEPAGED) &&
+ khugepaged_enter_vma_merge(vma, *vm_flags))
return -ENOMEM;
break;
case MADV_NOHUGEPAGE:
- /*
- * Be somewhat over-protective like KSM for now!
- */
- if (*vm_flags & VM_NO_THP)
- return -EINVAL;
*vm_flags &= ~VM_HUGEPAGE;
*vm_flags |= VM_NOHUGEPAGE;
/*
@@ -1974,7 +1965,7 @@ int khugepaged_enter_vma_merge(struct vm_area_struct *vma,
* page fault if needed.
*/
return 0;
- if (vma->vm_ops || (vm_flags & VM_NO_THP))
+ if (vma->vm_ops || (vm_flags & VM_NO_KHUGEPAGED))
/* khugepaged not yet working on file or special mappings */
return 0;
hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
@@ -2366,7 +2357,7 @@ static bool hugepage_vma_check(struct vm_area_struct *vma)
return false;
if (is_vma_temporary_stack(vma))
return false;
- return !(vma->vm_flags & VM_NO_THP);
+ return !(vma->vm_flags & VM_NO_KHUGEPAGED);
}
/*
diff --git a/mm/shmem.c b/mm/shmem.c
index 302ae4a0af3d..f19b6b44ae46 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -101,6 +101,8 @@ struct shmem_falloc {
enum sgp_type {
SGP_READ, /* don't exceed i_size, don't allocate page */
SGP_CACHE, /* don't exceed i_size, may allocate page */
+ SGP_NOHUGE, /* like SGP_CACHE, but no huge pages */
+ SGP_HUGE, /* like SGP_CACHE, huge pages preferred */
SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */
SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */
};
@@ -1409,6 +1411,7 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
struct mem_cgroup *memcg;
struct page *page;
swp_entry_t swap;
+ enum sgp_type sgp_huge = sgp;
pgoff_t hindex = index;
int error;
int once = 0;
@@ -1416,6 +1419,8 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
if (index > (MAX_LFS_FILESIZE >> PAGE_SHIFT))
return -EFBIG;
+ if (sgp == SGP_NOHUGE || sgp == SGP_HUGE)
+ sgp = SGP_CACHE;
repeat:
swap.val = 0;
page = find_lock_entry(mapping, index);
@@ -1534,7 +1539,7 @@ repeat:
/* shmem_symlink() */
if (mapping->a_ops != &shmem_aops)
goto alloc_nohuge;
- if (shmem_huge == SHMEM_HUGE_DENY)
+ if (shmem_huge == SHMEM_HUGE_DENY || sgp_huge == SGP_NOHUGE)
goto alloc_nohuge;
if (shmem_huge == SHMEM_HUGE_FORCE)
goto alloc_huge;
@@ -1551,7 +1556,9 @@ repeat:
goto alloc_huge;
/* fallthrough */
case SHMEM_HUGE_ADVISE:
- /* TODO: wire up fadvise()/madvise() */
+ if (sgp_huge == SGP_HUGE)
+ goto alloc_huge;
+ /* TODO: implement fadvise() hints */
goto alloc_nohuge;
}
@@ -1680,6 +1687,7 @@ static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct inode *inode = file_inode(vma->vm_file);
gfp_t gfp = mapping_gfp_mask(inode->i_mapping);
+ enum sgp_type sgp;
int error;
int ret = VM_FAULT_LOCKED;
@@ -1741,7 +1749,13 @@ static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
spin_unlock(&inode->i_lock);
}
- error = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, SGP_CACHE,
+ sgp = SGP_CACHE;
+ if (vma->vm_flags & VM_HUGEPAGE)
+ sgp = SGP_HUGE;
+ else if (vma->vm_flags & VM_NOHUGEPAGE)
+ sgp = SGP_NOHUGE;
+
+ error = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, sgp,
gfp, vma->vm_mm, &ret);
if (error)
return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS);