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-rw-r--r--include/linux/huge_mm.h6
-rw-r--r--mm/huge_memory.c23
-rw-r--r--mm/madvise.c2
3 files changed, 24 insertions, 7 deletions
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index a8b7e42..bddfba1 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -105,7 +105,8 @@ 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, int advice);
+extern int hugepage_madvise(struct vm_area_struct *vma,
+ unsigned long *vm_flags, int advice);
extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
@@ -143,7 +144,8 @@ 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, int advice)
+static inline int hugepage_madvise(struct vm_area_struct *vma,
+ unsigned long *vm_flags, int advice)
{
BUG();
return 0;
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index fce667c0..004c9c2 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1389,7 +1389,8 @@ out:
return ret;
}
-int hugepage_madvise(unsigned long *vm_flags, int advice)
+int hugepage_madvise(struct vm_area_struct *vma,
+ unsigned long *vm_flags, int advice)
{
switch (advice) {
case MADV_HUGEPAGE:
@@ -1404,6 +1405,13 @@ int hugepage_madvise(unsigned long *vm_flags, int advice)
return -EINVAL;
*vm_flags &= ~VM_NOHUGEPAGE;
*vm_flags |= VM_HUGEPAGE;
+ /*
+ * If the vma become good for khugepaged to scan,
+ * register it here without waiting a page fault that
+ * may not happen any time soon.
+ */
+ if (unlikely(khugepaged_enter_vma_merge(vma)))
+ return -ENOMEM;
break;
case MADV_NOHUGEPAGE:
/*
@@ -1417,6 +1425,11 @@ int hugepage_madvise(unsigned long *vm_flags, int advice)
return -EINVAL;
*vm_flags &= ~VM_HUGEPAGE;
*vm_flags |= VM_NOHUGEPAGE;
+ /*
+ * Setting VM_NOHUGEPAGE will prevent khugepaged from scanning
+ * this vma even if we leave the mm registered in khugepaged if
+ * it got registered before VM_NOHUGEPAGE was set.
+ */
break;
}
@@ -1784,7 +1797,8 @@ static void collapse_huge_page(struct mm_struct *mm,
if (address < hstart || address + HPAGE_PMD_SIZE > hend)
goto out;
- if (!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always())
+ if ((!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always()) ||
+ (vma->vm_flags & VM_NOHUGEPAGE))
goto out;
/* VM_PFNMAP vmas may have vm_ops null but vm_file set */
@@ -2007,8 +2021,9 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
break;
}
- if (!(vma->vm_flags & VM_HUGEPAGE) &&
- !khugepaged_always()) {
+ if ((!(vma->vm_flags & VM_HUGEPAGE) &&
+ !khugepaged_always()) ||
+ (vma->vm_flags & VM_NOHUGEPAGE)) {
progress++;
continue;
}
diff --git a/mm/madvise.c b/mm/madvise.c
index bbac126..2221491 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -73,7 +73,7 @@ static long madvise_behavior(struct vm_area_struct * vma,
break;
case MADV_HUGEPAGE:
case MADV_NOHUGEPAGE:
- error = hugepage_madvise(&new_flags, behavior);
+ error = hugepage_madvise(vma, &new_flags, behavior);
if (error)
goto out;
break;
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