Hi Yu,
On 3/1/2024 12:04 AM, Yu Zhao wrote:
> diff --git a/include/linux/gfp.h b/include/linux/gfp.h
> index de292a007138..c0f9d21b4d18 100644
> --- a/include/linux/gfp.h
> +++ b/include/linux/gfp.h
> @@ -88,8 +88,8 @@ static inline bool gfpflags_allow_blocking(const gfp_t gfp_flags)
> * GFP_ZONES_SHIFT must be <= 2 on 32 bit platforms.
> */
>
> -#if defined(CONFIG_ZONE_DEVICE) && (MAX_NR_ZONES-1) <= 4
> -/* ZONE_DEVICE is not a valid GFP zone specifier */
> +#if MAX_NR_ZONES - 2 - IS_ENABLED(CONFIG_ZONE_DEVICE) <= 4
> +/* zones beyond ZONE_MOVABLE are not valid GFP zone specifiers */
> #define GFP_ZONES_SHIFT 2
> #else
> #define GFP_ZONES_SHIFT ZONES_SHIFT
> @@ -135,9 +135,29 @@ static inline enum zone_type gfp_zone(gfp_t flags)
> z = (GFP_ZONE_TABLE >> (bit * GFP_ZONES_SHIFT)) &
> ((1 << GFP_ZONES_SHIFT) - 1);
> VM_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
> +
> + if ((flags & (__GFP_MOVABLE | __GFP_COMP)) == (__GFP_MOVABLE | __GFP_COMP))
> + return LAST_VIRT_ZONE;
> +
Not sure If someone had already reported this: With this patch, we allow
pages to allocate from movable zone(through fallback from
LAST_VIRT_ZONE) even with out __GFP_HIGHMEM. The commit cc09cb134124a
("mm/page_alloc: Add folio allocation functions") sets the __GFP_COMP by
default and user has just to pass the __GFP_MOVABLE. Please CMIW.
Thanks,
Charan
