[PATCH v5 4/7] mm: Introduce FPB_RESPECT_WRITE for PTE batching infrastructure

[Zi Yan]

On 18 Jul 2025, at 5:02, Dev Jain wrote:

> Patch 6 optimizes mprotect() by batch clearing the ptes, masking in the new

“Patch 6” might not make sense when reading it in the git log. Something like
below might be better:

mprotect() will be optimized by batch clearing the ptes, masking in the new
protections, and batch setting the ptes in an upcoming commit.

No need to repin for this one.

> protections, and batch setting the ptes. Suppose that the first pte
> of the batch is writable - with the current implementation of
> folio_pte_batch(), it is not guaranteed that the other ptes in the batch
> are already writable too, so we may incorrectly end up setting the
> writable bit on all ptes via modify_prot_commit_ptes().
>
> Therefore, introduce FPB_RESPECT_WRITE so that all ptes in the batch
> are writable or not.
>
> Signed-off-by: Dev Jain <dev.jain at arm.com>
> ---
>  mm/internal.h | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
>

LGTM. Reviewed-by: Zi Yan <ziy at nvidia.com>

Best Regards,
Yan, Zi