Re: [PATCH v2 1/2] fs/proc/task_mmu: do not warn on seeing non-migration pmd entry

From: Balbir Singh

Date: Sun May 31 2026 - 19:40:05 EST


On 5/30/26 18:54, Dev Jain wrote:
> pagemap_pmd_range_thp() warns if a non-present PMD is not a migration
> entry. This became false once device-private entries at the PMD level were
> added.
>
> Therefore, remove the stale migration-only assertion.
>
> Fixes: a30b48bf1b24 ("mm/migrate_device: implement THP migration of zone device pages")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Dev Jain <dev.jain@xxxxxxx>
> ---
> fs/proc/task_mmu.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> index 1e3a15bf46f4e..58938e62154d9 100644
> --- a/fs/proc/task_mmu.c
> +++ b/fs/proc/task_mmu.c
> @@ -2129,7 +2129,6 @@ static int pagemap_pmd_range_thp(pmd_t *pmdp, unsigned long addr,
> flags |= PM_SOFT_DIRTY;
> if (pmd_swp_uffd_wp(pmd))
> flags |= PM_UFFD_WP;
> - VM_WARN_ON_ONCE(!pmd_is_migration_entry(pmd));
> page = softleaf_to_page(entry);
> }
>

Thanks!
Reviewed-by: Balbir Singh <balbirs@xxxxxxxxxx>

Balbir