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Subject: Re: [RFC PATCH v2 1/9] mm: Add new mm flags for Copy-On-Write PTE
 table
Thread-Topic: [RFC PATCH v2 1/9] mm: Add new mm flags for Copy-On-Write PTE
 table
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Date:   Tue, 27 Sep 2022 17:23:58 +0000
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On Sep 27, 2022, at 9:29 AM, Chih-En Lin <shiyn.lin@gmail.com> wrote:

> Add MMF_COW_PTE{, _READY} flags to prepare the subsequent
> implementation of Copy-On-Write for the page table.
>=20
> Signed-off-by: Chih-En Lin <shiyn.lin@gmail.com>
> ---
> include/linux/sched/coredump.h | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>=20
> diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredum=
p.h
> index 4d0a5be28b70f..f03ff69c90c8c 100644
> --- a/include/linux/sched/coredump.h
> +++ b/include/linux/sched/coredump.h
> @@ -84,7 +84,13 @@ static inline int get_dumpable(struct mm_struct *mm)
> #define MMF_HAS_PINNED		28	/* FOLL_PIN has run, never cleared */
> #define MMF_DISABLE_THP_MASK	(1 << MMF_DISABLE_THP)
>=20
> +#define MMF_COW_PTE_READY	29
> +#define MMF_COW_PTE_READY_MASK	(1 << MMF_COW_PTE_READY)
> +
> +#define MMF_COW_PTE		30
> +#define MMF_COW_PTE_MASK	(1 << MMF_COW_PTE)

I am not sure how much sense it makes to put it in a separate patch, and it
is rather hard to understand the new flags without proper documentation and
comments.