Re: [PATCH v5 03/14] mm/huge_memory: remove READ_ONLY_THP_FOR_FS from file_thp_enabled()

[Nico Pache]

On 4/29/26 9:29 AM, Zi Yan wrote:
Replace it with a check on the max folio order of the file's address space
mapping, making sure PMD folio is supported. Keep the inode open-for-write
check, since even if collapse_file() now makes sure all to-be-collapsed
folios are clean and the created PMD file THP can be handled by FSes
properly, the filemap_flush() could perform undesirable write back.

Signed-off-by: Zi Yan <z...@nvidia.com>
---
  mm/huge_memory.c | 6 +++---
  1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 2f3fcb4dd1ef8..3b324f03e9283 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -86,9 +86,6 @@ static inline bool file_thp_enabled(struct vm_area_struct 
*vma)
  {
        struct inode *inode;
  
-	if (!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS))
-               return false;
-
        if (!vma->vm_file)
                return false;
  
@@ -97,6 +94,9 @@ static inline bool file_thp_enabled(struct vm_area_struct *vma)
        if (IS_ANON_FILE(inode))
                return false;
  
+	if (!mapping_pmd_folio_support(vma->vm_file->f_mapping))

Other than my question in the previous patch about >= PMD_ORDER vs == 
PMD_ORDER.

LGTM

Reviewed-by: Nico Pache <npa...@redhat.com>

+               return false;
+
        return !inode_is_open_for_write(inode) && S_ISREG(inode->i_mode);
  }