[PATCH v2 15/17] khugepaged: Delay cond_resched()
From: Dev Jain
Date: Tue Feb 11 2025 - 06:17:42 EST
Post scanning VMAs less than PMD-size, cond_resched() may get called at
a frequency of 1 << order worth of pte scan. Earlier, this was at a
PMD-worth scan. Therefore, manually enforce the previous behaviour; not
doing this causes the khugepaged selftest to timeout.
Signed-off-by: Dev Jain <dev.jain@xxxxxxx>
---
mm/khugepaged.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 7c9a758f6817..d2bb008b95e7 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -2650,6 +2650,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result,
unsigned long orders;
int order;
bool is_file_vma;
+ int prev_progress = 0;
VM_BUG_ON(!pages);
lockdep_assert_held(&khugepaged_mm_lock);
@@ -2730,7 +2731,10 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result,
while (khugepaged_scan.address < hend) {
bool mmap_locked = true;
- cond_resched();
+ if (progress - prev_progress >= HPAGE_PMD_NR) {
+ cond_resched();
+ prev_progress = progress;
+ }
if (unlikely(hpage_collapse_test_exit_or_disable(mm)))
goto breakouterloop;
--
2.30.2