Commit 23519073 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Linus Torvalds

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@linux.intel.comSigned-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ecf1385d
...@@ -43,6 +43,11 @@ int do_swap_page(struct vm_fault *vmf); ...@@ -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, void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
unsigned long floor, unsigned long ceiling); 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, void unmap_page_range(struct mmu_gather *tlb,
struct vm_area_struct *vma, struct vm_area_struct *vma,
unsigned long addr, unsigned long end, unsigned long addr, unsigned long end,
......
...@@ -25,6 +25,8 @@ ...@@ -25,6 +25,8 @@
#include <asm/tlb.h> #include <asm/tlb.h>
#include "internal.h"
/* /*
* Any behaviour which results in changes to the vma->vm_flags needs to * Any behaviour which results in changes to the vma->vm_flags needs to
* take mmap_sem for writing. Others, which simply traverse vmas, need * take mmap_sem for writing. Others, which simply traverse vmas, need
...@@ -474,7 +476,7 @@ static long madvise_dontneed(struct vm_area_struct *vma, ...@@ -474,7 +476,7 @@ static long madvise_dontneed(struct vm_area_struct *vma,
unsigned long start, unsigned long end) unsigned long start, unsigned long end)
{ {
*prev = vma; *prev = vma;
if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP)) if (!can_madv_dontneed_vma(vma))
return -EINVAL; return -EINVAL;
madvise_userfault_dontneed(vma, prev, start, end); madvise_userfault_dontneed(vma, prev, start, end);
......
...@@ -508,14 +508,7 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm) ...@@ -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); tlb_gather_mmu(&tlb, mm, 0, -1);
for (vma = mm->mmap ; vma; vma = vma->vm_next) { for (vma = mm->mmap ; vma; vma = vma->vm_next) {
if (is_vm_hugetlb_page(vma)) if (!can_madv_dontneed_vma(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; continue;
/* /*
......
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