diff options
| author | Baolin Wang <[email protected]> | 2024-10-14 18:24:44 +0800 |
|---|---|---|
| committer | Andrew Morton <[email protected]> | 2024-10-17 00:28:10 -0700 |
| commit | d60fcaf00d752c52fdf566d4184e6d04d9d08879 (patch) | |
| tree | 96fb13f785b37347d6f27f61b6e0527f0ca8fcd5 | |
| parent | 22ff9b0ff11a762852cd620972f265b3129e3fe7 (diff) | |
mm: khugepaged: fix the incorrect statistics when collapsing large file folios
Khugepaged already supports collapsing file large folios (including shmem
mTHP) by commit 7de856ffd007 ("mm: khugepaged: support shmem mTHP
collapse"), and the control parameters in khugepaged:
'khugepaged_max_ptes_swap' and 'khugepaged_max_ptes_none', still compare
based on PTE granularity to determine whether a file collapse is needed.
However, the statistics for 'present' and 'swap' in
hpage_collapse_scan_file() do not take into account the large folios,
which may lead to incorrect judgments regarding the
khugepaged_max_ptes_swap/none parameters, resulting in unnecessary file
collapses.
To fix this issue, take into account the large folios' statistics for
'present' and 'swap' variables in the hpage_collapse_scan_file().
Link: https://lkml.kernel.org/r/c76305d96d12d030a1a346b50503d148364246d2.1728901391.git.baolin.wang@linux.alibaba.com
Fixes: 7de856ffd007 ("mm: khugepaged: support shmem mTHP collapse")
Signed-off-by: Baolin Wang <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Reviewed-by: Barry Song <[email protected]>
Reviewed-by: Zi Yan <[email protected]>
Reviewed-by: Yang Shi <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Ryan Roberts <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
| -rw-r--r-- | mm/khugepaged.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index a420eff92011..b538c3d48386 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -2252,7 +2252,7 @@ static int hpage_collapse_scan_file(struct mm_struct *mm, unsigned long addr, continue; if (xa_is_value(folio)) { - ++swap; + swap += 1 << xas_get_order(&xas); if (cc->is_khugepaged && swap > khugepaged_max_ptes_swap) { result = SCAN_EXCEED_SWAP_PTE; @@ -2299,7 +2299,7 @@ static int hpage_collapse_scan_file(struct mm_struct *mm, unsigned long addr, * is just too costly... */ - present++; + present += folio_nr_pages(folio); if (need_resched()) { xas_pause(&xas); |