[PATCH v2 4/4] mm: khugepaged: set to next mm direct when mm has MMF_DISABLE_THP_COMPLETELY

[Vernon Yang]

When an mm with the MMF_DISABLE_THP_COMPLETELY flag is detected during
scanning, directly set khugepaged_scan.mm_slot to the next mm_slot,
reduce redundant operation.

Signed-off-by: Vernon Yang <yanglincheng@xxxxxxxxxx>
---
 mm/khugepaged.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 2b3685b195f5..72be87ef384b 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -2439,6 +2439,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result,
 
 		cond_resched();
 		if (unlikely(hpage_collapse_test_exit_or_disable(mm))) {
+			vma = NULL;
 			progress++;
 			break;
 		}
@@ -2459,8 +2460,10 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result,
 			bool mmap_locked = true;
 
 			cond_resched();
-			if (unlikely(hpage_collapse_test_exit_or_disable(mm)))
+			if (unlikely(hpage_collapse_test_exit_or_disable(mm))) {
+				vma = NULL;
 				goto breakouterloop;
+			}
 
 			VM_BUG_ON(khugepaged_scan.address < hstart ||
 				  khugepaged_scan.address + HPAGE_PMD_SIZE >
@@ -2477,8 +2480,10 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result,
 				fput(file);
 				if (*result == SCAN_PTE_MAPPED_HUGEPAGE) {
 					mmap_read_lock(mm);
-					if (hpage_collapse_test_exit_or_disable(mm))
+					if (hpage_collapse_test_exit_or_disable(mm)) {
+						vma = NULL;
 						goto breakouterloop;
+					}
 					*result = collapse_pte_mapped_thp(mm,
 						khugepaged_scan.address, false);
 					if (*result == SCAN_PMD_MAPPED)
-- 
2.51.0