6 files changed, 24 insertions, 10 deletions
diff --git a/arch/alpha/include/uapi/asm/mman.h b/arch/alpha/include/uapi/asm/mman.h
index 56b4ee5a6c9e..4aa996423b0d 100644
--- a/arch/alpha/include/uapi/asm/mman.h
+++ b/arch/alpha/include/uapi/asm/mman.h
@@ -74,6 +74,8 @@
 #define MADV_POPULATE_READ	22	/* populate (prefault) page tables readable */
 #define MADV_POPULATE_WRITE	23	/* populate (prefault) page tables writable */
 
+#define MADV_DONTNEED_LOCKED	24	/* like DONTNEED, but drop locked pages too */
+
 /* compatibility flags */
 #define MAP_FILE	0
 
diff --git a/arch/mips/include/uapi/asm/mman.h b/arch/mips/include/uapi/asm/mman.h
index 40b210c65a5a..1be428663c10 100644
--- a/arch/mips/include/uapi/asm/mman.h
+++ b/arch/mips/include/uapi/asm/mman.h
@@ -101,6 +101,8 @@
 #define MADV_POPULATE_READ	22	/* populate (prefault) page tables readable */
 #define MADV_POPULATE_WRITE	23	/* populate (prefault) page tables writable */
 
+#define MADV_DONTNEED_LOCKED	24	/* like DONTNEED, but drop locked pages too */
+
 /* compatibility flags */
 #define MAP_FILE	0
 
diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h
index 9e3c010c0f61..a7ea3204a5fa 100644
--- a/arch/parisc/include/uapi/asm/mman.h
+++ b/arch/parisc/include/uapi/asm/mman.h
@@ -55,6 +55,8 @@
 #define MADV_POPULATE_READ	22	/* populate (prefault) page tables readable */
 #define MADV_POPULATE_WRITE	23	/* populate (prefault) page tables writable */
 
+#define MADV_DONTNEED_LOCKED	24	/* like DONTNEED, but drop locked pages too */
+
 #define MADV_MERGEABLE   65		/* KSM may merge identical pages */
 #define MADV_UNMERGEABLE 66		/* KSM may not merge identical pages */
 
diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h
index b3a22095371b..7966a58af472 100644
--- a/arch/xtensa/include/uapi/asm/mman.h
+++ b/arch/xtensa/include/uapi/asm/mman.h
@@ -109,6 +109,8 @@
 #define MADV_POPULATE_READ	22	/* populate (prefault) page tables readable */
 #define MADV_POPULATE_WRITE	23	/* populate (prefault) page tables writable */
 
+#define MADV_DONTNEED_LOCKED	24	/* like DONTNEED, but drop locked pages too */
+
 /* compatibility flags */
 #define MAP_FILE	0
 
diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
index 1567a3294c3d..6c1aa92a92e4 100644
--- a/include/uapi/asm-generic/mman-common.h
+++ b/include/uapi/asm-generic/mman-common.h
@@ -75,6 +75,8 @@
 #define MADV_POPULATE_READ	22	/* populate (prefault) page tables readable */
 #define MADV_POPULATE_WRITE	23	/* populate (prefault) page tables writable */
 
+#define MADV_DONTNEED_LOCKED	24	/* like DONTNEED, but drop locked pages too */
+
 /* compatibility flags */
 #define MAP_FILE	0
 
diff --git a/mm/madvise.c b/mm/madvise.c
index 2e6213664c52..b41858ee937b 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -52,6 +52,7 @@ static int madvise_need_mmap_write(int behavior)
 	case MADV_REMOVE:
 	case MADV_WILLNEED:
 	case MADV_DONTNEED:
+	case MADV_DONTNEED_LOCKED:
 	case MADV_COLD:
 	case MADV_PAGEOUT:
 	case MADV_FREE:
@@ -502,14 +503,9 @@ static void madvise_cold_page_range(struct mmu_gather *tlb,
 	tlb_end_vma(tlb, vma);
 }
 
-static inline bool can_madv_lru_non_huge_vma(struct vm_area_struct *vma)
-{
-	return !(vma->vm_flags & (VM_LOCKED|VM_PFNMAP));
-}
-
 static inline bool can_madv_lru_vma(struct vm_area_struct *vma)
 {
-	return can_madv_lru_non_huge_vma(vma) && !is_vm_hugetlb_page(vma);
+	return !(vma->vm_flags & (VM_LOCKED|VM_PFNMAP|VM_HUGETLB));
 }
 
 static long madvise_cold(struct vm_area_struct *vma,
@@ -787,10 +783,16 @@ static bool madvise_dontneed_free_valid_vma(struct vm_area_struct *vma,
 					    unsigned long *end,
 					    int behavior)
 {
-	if (!is_vm_hugetlb_page(vma))
-		return can_madv_lru_non_huge_vma(vma);
+	if (!is_vm_hugetlb_page(vma)) {
+		unsigned int forbidden = VM_PFNMAP;
+
+		if (behavior != MADV_DONTNEED_LOCKED)
+			forbidden |= VM_LOCKED;
+
+		return !(vma->vm_flags & forbidden);
+	}
 
-	if (behavior != MADV_DONTNEED)
+	if (behavior != MADV_DONTNEED && behavior != MADV_DONTNEED_LOCKED)
 		return false;
 	if (start & ~huge_page_mask(hstate_vma(vma)))
 		return false;
@@ -854,7 +856,7 @@ static long madvise_dontneed_free(struct vm_area_struct *vma,
 		VM_WARN_ON(start >= end);
 	}
 
-	if (behavior == MADV_DONTNEED)
+	if (behavior == MADV_DONTNEED || behavior == MADV_DONTNEED_LOCKED)
 		return madvise_dontneed_single_vma(vma, start, end);
 	else if (behavior == MADV_FREE)
 		return madvise_free_single_vma(vma, start, end);
@@ -993,6 +995,7 @@ static int madvise_vma_behavior(struct vm_area_struct *vma,
 		return madvise_pageout(vma, prev, start, end);
 	case MADV_FREE:
 	case MADV_DONTNEED:
+	case MADV_DONTNEED_LOCKED:
 		return madvise_dontneed_free(vma, prev, start, end, behavior);
 	case MADV_POPULATE_READ:
 	case MADV_POPULATE_WRITE:
@@ -1123,6 +1126,7 @@ madvise_behavior_valid(int behavior)
 	case MADV_REMOVE:
 	case MADV_WILLNEED:
 	case MADV_DONTNEED:
+	case MADV_DONTNEED_LOCKED:
 	case MADV_FREE:
 	case MADV_COLD:
 	case MADV_PAGEOUT: