collapse_file() requires FSes supporting large folio with at least PMD_ORDER, so replace the READ_ONLY_THP_FOR_FS check with that. MADV_COLLAPSE ignores shmem huge config, so exclude the check for shmem.
While at it, replace VM_BUG_ON with VM_WARN_ON_ONCE. In collapse_scan_file(), add FS eligibility check to avoid redundant scans. Signed-off-by: Zi Yan <[email protected]> --- mm/khugepaged.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index b8452dbdb043..d2f0acd2dac2 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1892,8 +1892,9 @@ static enum scan_result collapse_file(struct mm_struct *mm, unsigned long addr, int nr_none = 0; bool is_shmem = shmem_file(file); - VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem); - VM_BUG_ON(start & (HPAGE_PMD_NR - 1)); + /* MADV_COLLAPSE ignores shmem huge config, so do not check shmem */ + VM_WARN_ON_ONCE(!is_shmem && mapping_max_folio_order(mapping) < PMD_ORDER); + VM_WARN_ON_ONCE(start & (HPAGE_PMD_NR - 1)); result = alloc_charge_folio(&new_folio, mm, cc); if (result != SCAN_SUCCEED) @@ -2321,6 +2322,13 @@ static enum scan_result collapse_scan_file(struct mm_struct *mm, int node = NUMA_NO_NODE; enum scan_result result = SCAN_SUCCEED; + /* + * skip files without PMD-order folio support + * do not check shmem, since MADV_COLLAPSE ignores shmem huge config + */ + if (!shmem_file(file) && mapping_max_folio_order(mapping) < PMD_ORDER) + return SCAN_FAIL; + present = 0; swap = 0; memset(cc->node_load, 0, sizeof(cc->node_load)); -- 2.43.0
