Re: [PATCH] mm: Introduce GFP_PGTABLE

From: Matthew Wilcox
Date: Sat Jan 12 2019 - 07:13:06 EST


On Sat, Jan 12, 2019 at 03:56:38PM +0530, Anshuman Khandual wrote:
> All architectures have been defining their own PGALLOC_GFP as (GFP_KERNEL |
> __GFP_ZERO) and using it for allocating page table pages.

Except that's not true.

> +++ b/arch/x86/mm/pgtable.c
> @@ -13,19 +13,17 @@ phys_addr_t physical_mask __ro_after_init = (1ULL << __PHYSICAL_MASK_SHIFT) - 1;
> EXPORT_SYMBOL(physical_mask);
> #endif
>
> -#define PGALLOC_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
> -
> #ifdef CONFIG_HIGHPTE

...

> pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
> {
> - return (pte_t *)__get_free_page(PGALLOC_GFP & ~__GFP_ACCOUNT);
> + return (pte_t *)__get_free_page(GFP_PGTABLE & ~__GFP_ACCOUNT);
> }

I think x86 was the only odd one out here, but you'll need to try again ...