On 2025/7/5 02:17, Kairui Song wrote:
> From: Kairui Song <kasong@tencent.com>
>
> Slightly tidy up the different handling of swap in and error handling
> for SWP_SYNCHRONOUS_IO and non-SWP_SYNCHRONOUS_IO devices. Now swapin
> will always use either shmem_swapin_direct or shmem_swapin_cluster,
> then check the result.
>
> Simplify the control flow and avoid a redundant goto label.
>
> Signed-off-by: Kairui Song <kasong@tencent.com>
> ---
> mm/shmem.c | 31 +++++++++++++------------------
> 1 file changed, 13 insertions(+), 18 deletions(-)
>
> diff --git a/mm/shmem.c b/mm/shmem.c
> index 1fe9a3eb92b1..782162c0c4e0 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -2327,33 +2327,28 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index,
> count_vm_event(PGMAJFAULT);
> count_memcg_event_mm(fault_mm, PGMAJFAULT);
> }
> - /* Skip swapcache for synchronous device. */
> if (data_race(si->flags & SWP_SYNCHRONOUS_IO)) {
> + /* Direct mTHP swapin skipping swap cache & readhaed */
> folio = shmem_swapin_direct(inode, vma, index, swap,
> index_entry, order, gfp);
> - if (!IS_ERR(folio)) {
> + if (IS_ERR(folio)) {
> + error = PTR_ERR(folio);
> + folio = NULL;
> + goto failed;
> + } else {
The 'else' can be avoided, otherwise LGTM.
> if (folio_test_large(folio))
> swap = index_entry;
> skip_swapcache = true;
> - goto alloced;
> }
> -
> - /*
> - * Direct swapin handled order 0 fallback already,
> - * if it failed, abort.
> - */
> - error = PTR_ERR(folio);
> - folio = NULL;
> - goto failed;
> - }
> - /* Cached swapin with readahead, only supports order 0 */
> - folio = shmem_swapin_cluster(swap, gfp, info, index);
> - if (!folio) {
> - error = -ENOMEM;
> - goto failed;
> + } else {
> + /* Cached swapin with readhaed, only supports order 0 */
> + folio = shmem_swapin_cluster(swap, gfp, info, index);
> + if (!folio) {
> + error = -ENOMEM;
> + goto failed;
> + }
> }
> }
> -alloced:
> if (order > folio_order(folio)) {
> /*
> * Swapin may get smaller folios due to various reasons: