From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Subject: oom-reaper: use madvise_dontneed() logic to decide if unmap the VMA 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. Link: http://lkml.kernel.org/r/20170118122429.43661-4-kirill.shutemov@xxxxxxxxxxxxxxx Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/internal.h | 5 +++++ mm/madvise.c | 4 +++- mm/oom_kill.c | 9 +-------- 3 files changed, 9 insertions(+), 9 deletions(-) diff -puN mm/internal.h~oom-reaper-use-madvise_dontneed-logic-to-decide-if-unmap-the-vma mm/internal.h --- a/mm/internal.h~oom-reaper-use-madvise_dontneed-logic-to-decide-if-unmap-the-vma +++ a/mm/internal.h @@ -43,6 +43,11 @@ 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 -puN mm/madvise.c~oom-reaper-use-madvise_dontneed-logic-to-decide-if-unmap-the-vma mm/madvise.c --- a/mm/madvise.c~oom-reaper-use-madvise_dontneed-logic-to-decide-if-unmap-the-vma +++ a/mm/madvise.c @@ -25,6 +25,8 @@ #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 @@ -474,7 +476,7 @@ static long madvise_dontneed(struct vm_a 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; madvise_userfault_dontneed(vma, prev, start, end); diff -puN mm/oom_kill.c~oom-reaper-use-madvise_dontneed-logic-to-decide-if-unmap-the-vma mm/oom_kill.c --- a/mm/oom_kill.c~oom-reaper-use-madvise_dontneed-logic-to-decide-if-unmap-the-vma +++ a/mm/oom_kill.c @@ -508,14 +508,7 @@ static bool __oom_reap_task_mm(struct ta 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; /* _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
