Logic on whether we can reap pages from the VMA should match what we have in madvise_dontneed(). In particular, we should skip, VM_PFNMAP VMAs, but we don't now.
Let's just extract condition on which we can shoot down pagesi from a VMA with MADV_DONTNEED into separate function and use it in both places. Signed-off-by: Kirill A. Shutemov <[email protected]> Acked-by: Michal Hocko <[email protected]> --- mm/internal.h | 5 +++++ mm/madvise.c | 4 +++- mm/oom_kill.c | 9 +-------- 3 files changed, 9 insertions(+), 9 deletions(-) diff --git a/mm/internal.h b/mm/internal.h index 44d68895a9b9..7430628bff34 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -41,6 +41,11 @@ int do_swap_page(struct vm_fault *vmf); void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma, unsigned long floor, unsigned long ceiling); +static inline bool can_madv_dontneed_vma(struct vm_area_struct *vma) +{ + return !(vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP)); +} + void unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long addr, unsigned long end, diff --git a/mm/madvise.c b/mm/madvise.c index aa4c502caecb..c53d8da9c8e6 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -24,6 +24,8 @@ #include <asm/tlb.h> +#include "internal.h" + /* * Any behaviour which results in changes to the vma->vm_flags needs to * take mmap_sem for writing. Others, which simply traverse vmas, need @@ -473,7 +475,7 @@ static long madvise_dontneed(struct vm_area_struct *vma, unsigned long start, unsigned long end) { *prev = vma; - if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP)) + if (!can_madv_dontneed_vma(vma)) return -EINVAL; zap_page_range(vma, start, end - start); diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 96a53ab0c9eb..b6d8ac4948db 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -508,14 +508,7 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm) tlb_gather_mmu(&tlb, mm, 0, -1); for (vma = mm->mmap ; vma; vma = vma->vm_next) { - if (is_vm_hugetlb_page(vma)) - continue; - - /* - * mlocked VMAs require explicit munlocking before unmap. - * Let's keep it simple here and skip such VMAs. - */ - if (vma->vm_flags & VM_LOCKED) + if (!can_madv_dontneed_vma(vma)) continue; /* -- 2.10.2
