Re: [PATCH 1/3] mm/khugepaged: remove unnecessary goto 'skip' label
From: Wei Yang <hidden>
Date: 2025-12-17 02:48:20
Also in:
linux-mm, lkml
On Tue, Dec 16, 2025 at 11:11:38AM +0000, Shivank Garg wrote:
quoted hunk ↗ jump to hunk
Replace 'goto skip' with actual logic for better code readability. No functional change. Signed-off-by: Shivank Garg <redacted> --- mm/khugepaged.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 6c8c35d3e0c9..107146f012b1 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c@@ -2442,14 +2442,15 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result,break; } if (!thp_vma_allowable_order(vma, vma->vm_flags, TVA_KHUGEPAGED, PMD_ORDER)) { -skip: progress++; continue; } hstart = round_up(vma->vm_start, HPAGE_PMD_SIZE); hend = round_down(vma->vm_end, HPAGE_PMD_SIZE); - if (khugepaged_scan.address > hend) - goto skip; + if (khugepaged_scan.address > hend) { + progress++; + continue; + }
Hi, Shivank
The change here looks good, while I come up with an question.
The @progress here seems record two things:
* number of pages scaned
* number of vma skipped
While in very rare case, we may miss to count the second case.
For example, we have following vmas in a process:
vma1 vma2
+----------------+------------+
|2M |1M |
+----------------+------------+
Let's assume vma1 is exactly HPAGE_PMD_SIZE and also HPAGE_PMD_SIZE aligned.
But vma2 is only half of HPAGE_PMD_SIZE.
When scan finish vma1 and start on vma2, we would have hstart = hend =
address. So we continue here but would not do real scan, since address == hend.
I am thinking whether this could handle it:
if (khugepaged_scan.address > hend || hend <= hstart) {
progress++;
continue;
}
Do you thinks I am correct on this?
if (khugepaged_scan.address < hstart) khugepaged_scan.address = hstart; VM_BUG_ON(khugepaged_scan.address & ~HPAGE_PMD_MASK); -- 2.43.0
-- Wei Yang Help you, Help me