[PATCH, RESEND 1/4] mm: drop zap_details::ignore_dirty

[PATCH, RESEND 1/4] mm: drop zap_details::ignore_dirty

[Kirill A. Shutemov]

The only user of ignore_dirty is oom-reaper. But it doesn't really use
it.

ignore_dirty only has effect on file pages mapped with dirty pte.
But oom-repear skips shared VMAs, so there's no way we can dirty file
pte in them.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
---
 include/linux/mm.h | 1 -
 mm/memory.c        | 6 ------
 mm/oom_kill.c      | 3 +--
 3 files changed, 1 insertion(+), 9 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index b84615b0f64c..88beebe1e695 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1148,7 +1148,6 @@ struct zap_details {
 	struct address_space *check_mapping;	/* Check page->mapping if set */
 	pgoff_t	first_index;			/* Lowest page->index to unmap */
 	pgoff_t last_index;			/* Highest page->index to unmap */
-	bool ignore_dirty;			/* Ignore dirty pages */
 	bool check_swap_entries;		/* Check also swap entries */
 };
 
diff --git a/mm/memory.c b/mm/memory.c
index 6bf2b471e30c..1d8ef8ec1b48 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1155,12 +1155,6 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
 
 			if (!PageAnon(page)) {
 				if (pte_dirty(ptent)) {
-					/*
-					 * oom_reaper cannot tear down dirty
-					 * pages
-					 */
-					if (unlikely(details && details->ignore_dirty))
-						continue;
 					force_flush = 1;
 					set_page_dirty(page);
 				}
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index ec9f11d4f094..f101db68e760 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -465,8 +465,7 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
 {
 	struct mmu_gather tlb;
 	struct vm_area_struct *vma;
-	struct zap_details details = {.check_swap_entries = true,
-				      .ignore_dirty = true};
+	struct zap_details details = {.check_swap_entries = true};
 	bool ret = true;
 
 	/*
-- 
2.11.0

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[PATCH, RESEND 2/4] mm: drop zap_details::check_swap_entries

[Kirill A. Shutemov]

detail == NULL would give the same functionality as
.check_swap_entries==true.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
---
 include/linux/mm.h | 1 -
 mm/memory.c        | 4 ++--
 mm/oom_kill.c      | 3 +--
 3 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 88beebe1e695..ce5e9a9bf642 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1148,7 +1148,6 @@ struct zap_details {
 	struct address_space *check_mapping;	/* Check page->mapping if set */
 	pgoff_t	first_index;			/* Lowest page->index to unmap */
 	pgoff_t last_index;			/* Highest page->index to unmap */
-	bool check_swap_entries;		/* Check also swap entries */
 };
 
 struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
diff --git a/mm/memory.c b/mm/memory.c
index 1d8ef8ec1b48..5dbd0ce95815 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1173,8 +1173,8 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
 			}
 			continue;
 		}
-		/* only check swap_entries if explicitly asked for in details */
-		if (unlikely(details && !details->check_swap_entries))
+		/* If details->check_mapping, we leave swap entries. */
+		if (unlikely(details))
 			continue;
 
 		entry = pte_to_swp_entry(ptent);
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index f101db68e760..96a53ab0c9eb 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -465,7 +465,6 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
 {
 	struct mmu_gather tlb;
 	struct vm_area_struct *vma;
-	struct zap_details details = {.check_swap_entries = true};
 	bool ret = true;
 
 	/*
@@ -531,7 +530,7 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
 		 */
 		if (vma_is_anonymous(vma) || !(vma->vm_flags & VM_SHARED))
 			unmap_page_range(&tlb, vma, vma->vm_start, vma->vm_end,
-					 &details);
+					 NULL);
 	}
 	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",
-- 
2.11.0

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[PATCH, RESEND 3/4] mm: drop unused argument of zap_page_range()

[Kirill A. Shutemov]

There's no users of zap_page_range() who wants non-NULL 'details'.
Let's drop it.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
---
 arch/s390/mm/gmap.c               | 2 +-
 arch/x86/mm/mpx.c                 | 2 +-
 drivers/android/binder.c          | 2 +-
 drivers/staging/android/ion/ion.c | 3 +--
 include/linux/mm.h                | 2 +-
 mm/madvise.c                      | 2 +-
 mm/memory.c                       | 5 ++---
 7 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index ec1f0dedb948..59ac93714fa4 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -687,7 +687,7 @@ void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to)
 		/* Find vma in the parent mm */
 		vma = find_vma(gmap->mm, vmaddr);
 		size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK));
-		zap_page_range(vma, vmaddr, size, NULL);
+		zap_page_range(vma, vmaddr, size);
 	}
 	up_read(&gmap->mm->mmap_sem);
 }
diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
index af59f808742f..aad4ac386f98 100644
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -796,7 +796,7 @@ static noinline int zap_bt_entries_mapping(struct mm_struct *mm,
 			return -EINVAL;
 
 		len = min(vma->vm_end, end) - addr;
-		zap_page_range(vma, addr, len, NULL);
+		zap_page_range(vma, addr, len);
 		trace_mpx_unmap_zap(addr, addr+len);
 
 		vma = vma->vm_next;
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 3c71b982bf2a..d97f6725cf8c 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -629,7 +629,7 @@ static int binder_update_page_range(struct binder_proc *proc, int allocate,
 		page = &proc->pages[(page_addr - proc->buffer) / PAGE_SIZE];
 		if (vma)
 			zap_page_range(vma, (uintptr_t)page_addr +
-				proc->user_buffer_offset, PAGE_SIZE, NULL);
+				proc->user_buffer_offset, PAGE_SIZE);
 err_vm_insert_page_failed:
 		unmap_kernel_range((unsigned long)page_addr, PAGE_SIZE);
 err_map_kernel_failed:
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index b653451843c8..0fb0e28ace70 100644
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -865,8 +865,7 @@ static void ion_buffer_sync_for_device(struct ion_buffer *buffer,
 	list_for_each_entry(vma_list, &buffer->vmas, list) {
 		struct vm_area_struct *vma = vma_list->vma;
 
-		zap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start,
-			       NULL);
+		zap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start);
 	}
 	mutex_unlock(&buffer->lock);
 }
diff --git a/include/linux/mm.h b/include/linux/mm.h
index ce5e9a9bf642..6cb35e52044d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1158,7 +1158,7 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
 int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
 		unsigned long size);
 void zap_page_range(struct vm_area_struct *vma, unsigned long address,
-		unsigned long size, struct zap_details *);
+		unsigned long size);
 void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
 		unsigned long start, unsigned long end);
 
diff --git a/mm/madvise.c b/mm/madvise.c
index 0e3828eae9f8..aa4c502caecb 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -476,7 +476,7 @@ static long madvise_dontneed(struct vm_area_struct *vma,
 	if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP))
 		return -EINVAL;
 
-	zap_page_range(vma, start, end - start, NULL);
+	zap_page_range(vma, start, end - start);
 	return 0;
 }
 
diff --git a/mm/memory.c b/mm/memory.c
index 5dbd0ce95815..d7b96487cbb1 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1370,12 +1370,11 @@ void unmap_vmas(struct mmu_gather *tlb,
  * @vma: vm_area_struct holding the applicable pages
  * @start: starting address of pages to zap
  * @size: number of bytes to zap
- * @details: details of shared cache invalidation
  *
  * Caller must protect the VMA list
  */
 void zap_page_range(struct vm_area_struct *vma, unsigned long start,
-		unsigned long size, struct zap_details *details)
+		unsigned long size)
 {
 	struct mm_struct *mm = vma->vm_mm;
 	struct mmu_gather tlb;
@@ -1386,7 +1385,7 @@ void zap_page_range(struct vm_area_struct *vma, unsigned long start,
 	update_hiwater_rss(mm);
 	mmu_notifier_invalidate_range_start(mm, start, end);
 	for ( ; vma && vma->vm_start < end; vma = vma->vm_next)
-		unmap_single_vma(&tlb, vma, start, end, details);
+		unmap_single_vma(&tlb, vma, start, end, NULL);
 	mmu_notifier_invalidate_range_end(mm, start, end);
 	tlb_finish_mmu(&tlb, start, end);
 }
-- 
2.11.0

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[PATCH, RESEND 4/4] oom-reaper: use madvise_dontneed() logic to decide if unmap the VMA

[Kirill A. Shutemov]

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 <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
---
 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 7aa2ea0a8623..03763f5c42c5 100644
--- a/mm/internal.h
+++ b/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 --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;
 
 		/*
-- 
2.11.0

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