diff --git a/arch/alpha/include/uapi/asm/mman.h b/arch/alpha/include/uapi/asm/mman.h
index 4aa996423b0d..763929e814e9 100644
--- a/arch/alpha/include/uapi/asm/mman.h
+++ b/arch/alpha/include/uapi/asm/mman.h
@@ -76,6 +76,8 @@
 
 #define MADV_DONTNEED_LOCKED	24	/* like DONTNEED, but drop locked pages too */
 
+#define MADV_COLLAPSE	25		/* Synchronous hugepage collapse */
+
 /* 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 1be428663c10..c6e1fc77c996 100644
--- a/arch/mips/include/uapi/asm/mman.h
+++ b/arch/mips/include/uapi/asm/mman.h
@@ -103,6 +103,8 @@
 
 #define MADV_DONTNEED_LOCKED	24	/* like DONTNEED, but drop locked pages too */
 
+#define MADV_COLLAPSE	25		/* Synchronous hugepage collapse */
+
 /* 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 a7ea3204a5fa..22133a6a506e 100644
--- a/arch/parisc/include/uapi/asm/mman.h
+++ b/arch/parisc/include/uapi/asm/mman.h
@@ -70,6 +70,8 @@
 #define MADV_WIPEONFORK 71		/* Zero memory on fork, child only */
 #define MADV_KEEPONFORK 72		/* Undo MADV_WIPEONFORK */
 
+#define MADV_COLLAPSE	73		/* Synchronous hugepage collapse */
+
 #define MADV_HWPOISON     100		/* poison a page for testing */
 #define MADV_SOFT_OFFLINE 101		/* soft offline page for testing */
 
diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h
index 7966a58af472..1ff0c858544f 100644
--- a/arch/xtensa/include/uapi/asm/mman.h
+++ b/arch/xtensa/include/uapi/asm/mman.h
@@ -111,6 +111,8 @@
 
 #define MADV_DONTNEED_LOCKED	24	/* like DONTNEED, but drop locked pages too */
 
+#define MADV_COLLAPSE	25		/* Synchronous hugepage collapse */
+
 /* compatibility flags */
 #define MAP_FILE	0
 
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 816a9937f30e..ddad7c7af44e 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -236,6 +236,9 @@ void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
 
 int hugepage_madvise(struct vm_area_struct *vma, unsigned long *vm_flags,
 		     int advice);
+int madvise_collapse(struct vm_area_struct *vma,
+		     struct vm_area_struct **prev,
+		     unsigned long start, unsigned long end);
 void vma_adjust_trans_huge(struct vm_area_struct *vma, unsigned long start,
 			   unsigned long end, long adjust_next);
 spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma);
@@ -392,6 +395,15 @@ static inline int hugepage_madvise(struct vm_area_struct *vma,
 	BUG();
 	return 0;
 }
+
+static inline int madvise_collapse(struct vm_area_struct *vma,
+				   struct vm_area_struct **prev,
+				   unsigned long start, unsigned long end)
+{
+	BUG();
+	return 0;
+}
+
 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
 					 unsigned long start,
 					 unsigned long end,
diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
index 6c1aa92a92e4..6ce1f1ceb432 100644
--- a/include/uapi/asm-generic/mman-common.h
+++ b/include/uapi/asm-generic/mman-common.h
@@ -77,6 +77,8 @@
 
 #define MADV_DONTNEED_LOCKED	24	/* like DONTNEED, but drop locked pages too */
 
+#define MADV_COLLAPSE	25		/* Synchronous hugepage collapse */
+
 /* compatibility flags */
 #define MAP_FILE	0
 
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 0e4f5fbe00d2..098919d0324b 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -847,6 +847,23 @@ static inline gfp_t alloc_hugepage_khugepaged_gfpmask(void)
 	return khugepaged_defrag() ? GFP_TRANSHUGE : GFP_TRANSHUGE_LIGHT;
 }
 
+static struct page *alloc_hpage(struct collapse_control *cc, gfp_t gfp,
+				int node)
+{
+	VM_BUG_ON_PAGE(cc->hpage, cc->hpage);
+
+	cc->hpage = __alloc_pages_node(node, gfp, HPAGE_PMD_ORDER);
+	if (unlikely(!cc->hpage)) {
+		count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
+		cc->hpage = ERR_PTR(-ENOMEM);
+		return NULL;
+	}
+
+	prep_transhuge_page(cc->hpage);
+	count_vm_event(THP_COLLAPSE_ALLOC);
+	return cc->hpage;
+}
+
 #ifdef CONFIG_NUMA
 static int khugepaged_find_target_node(struct collapse_control *cc)
 {
@@ -893,18 +910,7 @@ static bool khugepaged_prealloc_page(struct page **hpage, bool *wait)
 static struct page *khugepaged_alloc_page(struct collapse_control *cc,
 					  gfp_t gfp, int node)
 {
-	VM_BUG_ON_PAGE(cc->hpage, cc->hpage);
-
-	cc->hpage = __alloc_pages_node(node, gfp, HPAGE_PMD_ORDER);
-	if (unlikely(!cc->hpage)) {
-		count_vm_event(THP_COLLAPSE_ALLOC_FAILED);
-		cc->hpage = ERR_PTR(-ENOMEM);
-		return NULL;
-	}
-
-	prep_transhuge_page(cc->hpage);
-	count_vm_event(THP_COLLAPSE_ALLOC);
-	return cc->hpage;
+	return alloc_hpage(cc, gfp, node);
 }
 #else
 static int khugepaged_find_target_node(struct collapse_control *cc)
@@ -2471,3 +2477,131 @@ void khugepaged_min_free_kbytes_update(void)
 		set_recommended_min_free_kbytes();
 	mutex_unlock(&khugepaged_mutex);
 }
+
+static inline gfp_t alloc_hugepage_madvise_gfpmask(void)
+{
+	return GFP_TRANSHUGE;
+}
+
+static void madvise_collapse_cleanup_page(struct page **hpage)
+{
+	if (!IS_ERR(*hpage) && *hpage)
+		put_page(*hpage);
+	*hpage = NULL;
+}
+
+static int madvise_collapse_errno(enum scan_result r)
+{
+	switch (r) {
+	case SCAN_PMD_NULL:
+	case SCAN_ADDRESS_RANGE:
+	case SCAN_VMA_NULL:
+	case SCAN_PTE_NON_PRESENT:
+	case SCAN_PAGE_NULL:
+		/*
+		 * Addresses in the specified range are not currently mapped,
+		 * or are outside the AS of the process.
+		 */
+		return -ENOMEM;
+	case SCAN_ALLOC_HUGE_PAGE_FAIL:
+	case SCAN_CGROUP_CHARGE_FAIL:
+		/* A kernel resource was temporarily unavailable. */
+		return -EAGAIN;
+	default:
+		return -EINVAL;
+	}
+}
+
+int madvise_collapse(struct vm_area_struct *vma, struct vm_area_struct **prev,
+		     unsigned long start, unsigned long end)
+{
+	struct collapse_control cc = {
+		.last_target_node = NUMA_NO_NODE,
+		.hpage = NULL,
+		.gfp = &alloc_hugepage_madvise_gfpmask,
+		.alloc_hpage = &alloc_hpage,
+	};
+	struct mm_struct *mm = vma->vm_mm;
+	struct collapse_result cr;
+	unsigned long hstart, hend, addr;
+	int thps = 0, nr_hpages = 0;
+
+	BUG_ON(vma->vm_start > start);
+	BUG_ON(vma->vm_end < end);
+
+	*prev = vma;
+
+	if (IS_ENABLED(CONFIG_SHMEM) && vma->vm_file)
+		return -EINVAL;
+
+	hstart = (start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK;
+	hend = end & HPAGE_PMD_MASK;
+	nr_hpages = (hend - hstart) >> HPAGE_PMD_SHIFT;
+
+	if (hstart >= hend || !transparent_hugepage_active(vma))
+		return -EINVAL;
+
+	mmgrab(mm);
+	lru_add_drain();
+
+	for (addr = hstart; ; ) {
+		mmap_assert_locked(mm);
+		cond_resched();
+		memset(&cr, 0, sizeof(cr));
+
+		if (unlikely(khugepaged_test_exit(mm))) {
+			cr.result = SCAN_ANY_PROCESS;
+			break;
+		}
+
+		memset(cc.node_load, 0, sizeof(cc.node_load));
+		khugepaged_scan_pmd(mm, vma, addr, &cc, &cr);
+		if (cr.dropped_mmap_lock)
+			*prev = NULL;  /* tell madvise we dropped mmap_lock */
+
+		switch (cr.result) {
+		/* Whitelisted set of results where continuing OK */
+		case SCAN_SUCCEED:
+		case SCAN_PMD_MAPPED:
+			++thps;
+		case SCAN_PMD_NULL:
+		case SCAN_PTE_NON_PRESENT:
+		case SCAN_PTE_UFFD_WP:
+		case SCAN_PAGE_RO:
+		case SCAN_LACK_REFERENCED_PAGE:
+		case SCAN_PAGE_NULL:
+		case SCAN_PAGE_COUNT:
+		case SCAN_PAGE_LOCK:
+		case SCAN_PAGE_COMPOUND:
+			break;
+		case SCAN_PAGE_LRU:
+			lru_add_drain_all();
+			goto retry;
+		default:
+			/* Other error, exit */
+			goto break_loop;
+		}
+		addr += HPAGE_PMD_SIZE;
+		if (addr >= hend)
+			break;
+retry:
+		if (cr.dropped_mmap_lock) {
+			mmap_read_lock(mm);
+			cr.result = hugepage_vma_revalidate(mm, addr, &vma);
+			if (cr.result)
+				goto out;
+		}
+		madvise_collapse_cleanup_page(&cc.hpage);
+	}
+
+break_loop:
+	/* madvise_walk_vmas() expects us to hold mmap_lock on return */
+	if (cr.dropped_mmap_lock)
+		mmap_read_lock(mm);
+out:
+	mmap_assert_locked(mm);
+	madvise_collapse_cleanup_page(&cc.hpage);
+	mmdrop(mm);
+
+	return thps == nr_hpages ? 0 : madvise_collapse_errno(cr.result);
+}
diff --git a/mm/madvise.c b/mm/madvise.c
index 5f4537511532..638517952bd2 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -59,6 +59,7 @@ static int madvise_need_mmap_write(int behavior)
 	case MADV_FREE:
 	case MADV_POPULATE_READ:
 	case MADV_POPULATE_WRITE:
+	case MADV_COLLAPSE:
 		return 0;
 	default:
 		/* be safe, default to 1. list exceptions explicitly */
@@ -1054,6 +1055,8 @@ static int madvise_vma_behavior(struct vm_area_struct *vma,
 		if (error)
 			goto out;
 		break;
+	case MADV_COLLAPSE:
+		return madvise_collapse(vma, prev, start, end);
 	}
 
 	anon_name = anon_vma_name(vma);
@@ -1147,6 +1150,7 @@ madvise_behavior_valid(int behavior)
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 	case MADV_HUGEPAGE:
 	case MADV_NOHUGEPAGE:
+	case MADV_COLLAPSE:
 #endif
 	case MADV_DONTDUMP:
 	case MADV_DODUMP:
@@ -1336,6 +1340,7 @@ int madvise_set_anon_name(struct mm_struct *mm, unsigned long start,
  *  MADV_NOHUGEPAGE - mark the given range as not worth being backed by
  *		transparent huge pages so the existing pages will not be
  *		coalesced into THP and new pages will not be allocated as THP.
+ *  MADV_COLLAPSE - synchronously coalesce pages into new THP.
  *  MADV_DONTDUMP - the application wants to prevent pages in the given range
  *		from being included in its core dump.
  *  MADV_DODUMP - cancel MADV_DONTDUMP: no longer exclude from core dump.
