2021-04-08 19:18:02

by Zack Rusin

Subject: [PATCH] mm/mapping_dirty_helpers: Guard hugepage pud's usage

Lets make sure we don't use pud hugepage helpers on architectures
which do not support it. This fixes the code on arm64.

Signed-off-by: Zack Rusin <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Thomas Hellström (Intel) <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
mm/mapping_dirty_helpers.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/mm/mapping_dirty_helpers.c b/mm/mapping_dirty_helpers.c
index b59054ef2e10..b890854ec761 100644
--- a/mm/mapping_dirty_helpers.c
+++ b/mm/mapping_dirty_helpers.c
@@ -165,10 +165,12 @@ static int wp_clean_pud_entry(pud_t *pud, unsigned long addr, unsigned long end,
return 0;
}

+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
/* Huge pud */
walk->action = ACTION_CONTINUE;
if (pud_trans_huge(pudval) || pud_devmap(pudval))
WARN_ON(pud_write(pudval) || pud_dirty(pudval));
+#endif

return 0;
}
--
2.27.0

2021-04-09 07:46:04

by Thomas Hellström (Intel)

Subject: Re: [PATCH] mm/mapping_dirty_helpers: Guard hugepage pud's usage

On 4/8/21 9:15 PM, Zack Rusin wrote:
> Lets make sure we don't use pud hugepage helpers on architectures
> which do not support it. This fixes the code on arm64.
nits:

Perhaps be a little more specific about what it fixes? I figure it's a
compilation failure?
Also please use imperative form: "Fix the code arm64" rather than "This
fixes the code on arm64"

Other than that LGTM.

Reviewed-by: Thomas Hellström (Intel) <[email protected]>


>
> Signed-off-by: Zack Rusin <[email protected]>
> Cc: Andrew Morton <[email protected]>
> Cc: Thomas Hellström (Intel) <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> ---
> mm/mapping_dirty_helpers.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/mm/mapping_dirty_helpers.c b/mm/mapping_dirty_helpers.c
> index b59054ef2e10..b890854ec761 100644
> --- a/mm/mapping_dirty_helpers.c
> +++ b/mm/mapping_dirty_helpers.c
> @@ -165,10 +165,12 @@ static int wp_clean_pud_entry(pud_t *pud, unsigned long addr, unsigned long end,
> return 0;
> }
>
> +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
> /* Huge pud */
> walk->action = ACTION_CONTINUE;
> if (pud_trans_huge(pudval) || pud_devmap(pudval))
> WARN_ON(pud_write(pudval) || pud_dirty(pudval));
> +#endif
>
> return 0;
> }