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 call madvise_dontneed() from __oom_reap_task_mm(), so we won't need to sync the logic in the future. Signed-off-by: Kirill A. Shutemov <[email protected]> --- mm/internal.h | 7 +++---- mm/madvise.c | 2 +- mm/memory.c | 2 +- mm/oom_kill.c | 15 ++------------- 4 files changed, 7 insertions(+), 19 deletions(-) diff --git a/mm/internal.h b/mm/internal.h index 44d68895a9b9..5c355855e4ad 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -41,10 +41,9 @@ 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); -void unmap_page_range(struct mmu_gather *tlb, - struct vm_area_struct *vma, - unsigned long addr, unsigned long end, - struct zap_details *details); +long madvise_dontneed(struct vm_area_struct *vma, + struct vm_area_struct **prev, + unsigned long start, unsigned long end); extern int __do_page_cache_readahead(struct address_space *mapping, struct file *filp, pgoff_t offset, unsigned long nr_to_read, diff --git a/mm/madvise.c b/mm/madvise.c index aa4c502caecb..8c9f19b62b4a 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -468,7 +468,7 @@ static long madvise_free(struct vm_area_struct *vma, * An interface that causes the system to free clean pages and flush * dirty pages is already available as msync(MS_INVALIDATE). */ -static long madvise_dontneed(struct vm_area_struct *vma, +long madvise_dontneed(struct vm_area_struct *vma, struct vm_area_struct **prev, unsigned long start, unsigned long end) { diff --git a/mm/memory.c b/mm/memory.c index eed102070dcb..f8836232a492 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1271,7 +1271,7 @@ static inline unsigned long zap_pud_range(struct mmu_gather *tlb, return addr; } -void unmap_page_range(struct mmu_gather *tlb, +static void unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long addr, unsigned long end, struct zap_details *details) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 96a53ab0c9eb..59a00b1c3145 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -479,7 +479,7 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm) * out_of_memory * select_bad_process * # no TIF_MEMDIE task selects new victim - * unmap_page_range # frees some memory + * madvise_dontneed # frees some memory */ mutex_lock(&oom_lock); @@ -508,16 +508,6 @@ 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) - continue; - /* * Only anonymous pages have a good chance to be dropped * without additional steps which we cannot afford as we @@ -529,8 +519,7 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm) * count elevated without a good reason. */ if (vma_is_anonymous(vma) || !(vma->vm_flags & VM_SHARED)) - unmap_page_range(&tlb, vma, vma->vm_start, vma->vm_end, - NULL); + madvise_dontneed(vma, &vma, vma->vm_start, vma->vm_end); } tlb_finish_mmu(&tlb, 0, -1); pr_info("oom_reaper: reaped process %d (%s), now anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n", -- 2.10.2
