linux-kernel - [RFC 02/11] khugepaged: refactor madvise_collapse and khugepaged_scan_mm

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Message-ID: <20250108233128.14484-3-npache@redhat.com>
Date: Wed,  8 Jan 2025 16:31:18 -0700
From: Nico Pache <npache@...hat.com>
To: linux-kernel@...r.kernel.org,
	linux-mm@...ck.org
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Subject: [RFC 02/11] khugepaged: refactor madvise_collapse and khugepaged_scan_mm_slot

Now that we have a khugepaged_collapse_single_pmd, lets use that code
in madvise_collapse and khugepaged_scan_mm_slot to create a single entry
point.

Signed-off-by: Nico Pache <npache@...hat.com>
---
 mm/khugepaged.c | 50 ++++---------------------------------------------
 1 file changed, 4 insertions(+), 46 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 4d932839ff1d..ba85a8fcee88 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -2468,33 +2468,9 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result,
 			VM_BUG_ON(khugepaged_scan.address < hstart ||
 				  khugepaged_scan.address + HPAGE_PMD_SIZE >
 				  hend);
-			if (IS_ENABLED(CONFIG_SHMEM) && vma->vm_file) {
-				struct file *file = get_file(vma->vm_file);
-				pgoff_t pgoff = linear_page_index(vma,
-						khugepaged_scan.address);
 
-				mmap_read_unlock(mm);
-				mmap_locked = false;
-				*result = hpage_collapse_scan_file(mm,
-					khugepaged_scan.address, file, pgoff, cc);
-				fput(file);
-				if (*result == SCAN_PTE_MAPPED_HUGEPAGE) {
-					mmap_read_lock(mm);
-					if (hpage_collapse_test_exit_or_disable(mm))
-						goto breakouterloop;
-					*result = collapse_pte_mapped_thp(mm,
-						khugepaged_scan.address, false);
-					if (*result == SCAN_PMD_MAPPED)
-						*result = SCAN_SUCCEED;
-					mmap_read_unlock(mm);
-				}
-			} else {
-				*result = hpage_collapse_scan_pmd(mm, vma,
-					khugepaged_scan.address, &mmap_locked, cc);
-			}
-
-			if (*result == SCAN_SUCCEED)
-				++khugepaged_pages_collapsed;
+			*result = khugepaged_collapse_single_pmd(khugepaged_scan.address,
+						mm, vma, &mmap_locked, cc);
 
 			/* move to next address */
 			khugepaged_scan.address += HPAGE_PMD_SIZE;
@@ -2814,36 +2790,18 @@ int madvise_collapse(struct vm_area_struct *vma, struct vm_area_struct **prev,
 		mmap_assert_locked(mm);
 		memset(cc->node_load, 0, sizeof(cc->node_load));
 		nodes_clear(cc->alloc_nmask);
-		if (IS_ENABLED(CONFIG_SHMEM) && vma->vm_file) {
-			struct file *file = get_file(vma->vm_file);
-			pgoff_t pgoff = linear_page_index(vma, addr);
 
-			mmap_read_unlock(mm);
-			mmap_locked = false;
-			result = hpage_collapse_scan_file(mm, addr, file, pgoff,
-							  cc);
-			fput(file);
-		} else {
-			result = hpage_collapse_scan_pmd(mm, vma, addr,
-							 &mmap_locked, cc);
-		}
+		result = khugepaged_collapse_single_pmd(addr, mm, vma, &mmap_locked, cc);
+
 		if (!mmap_locked)
 			*prev = NULL;  /* Tell caller we dropped mmap_lock */
 
-handle_result:
 		switch (result) {
 		case SCAN_SUCCEED:
 		case SCAN_PMD_MAPPED:
 			++thps;
 			break;
 		case SCAN_PTE_MAPPED_HUGEPAGE:
-			BUG_ON(mmap_locked);
-			BUG_ON(*prev);
-			mmap_read_lock(mm);
-			result = collapse_pte_mapped_thp(mm, addr, true);
-			mmap_read_unlock(mm);
-			goto handle_result;
-		/* Whitelisted set of results where continuing OK */
 		case SCAN_PMD_NULL:
 		case SCAN_PTE_NON_PRESENT:
 		case SCAN_PTE_UFFD_WP:
-- 
2.47.1