Re: [PATCH 14/15] um: switch to generic version of pte allocation

Anton Ivanov
2019-05-03T13:28:56Z

On 02/05/2019 16:28, Mike Rapoport wrote:
> um allocates PTE pages with __get_free_page() and uses
> GFP_KERNEL | __GFP_ZERO for the allocations.
>
> Switch it to the generic version that does exactly the same thing for the
> kernel page tables and adds __GFP_ACCOUNT for the user PTEs.
>
> The pte_free() and pte_free_kernel() versions are identical to the generic
> ones and can be simply dropped.
>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> ---
> arch/um/include/asm/pgalloc.h | 16 ++--------------
> arch/um/kernel/mem.c | 22 ----------------------
> 2 files changed, 2 insertions(+), 36 deletions(-)
>
> diff --git a/arch/um/include/asm/pgalloc.h b/arch/um/include/asm/pgalloc.h
> index 99eb568..d7b282e 100644
> --- a/arch/um/include/asm/pgalloc.h
> +++ b/arch/um/include/asm/pgalloc.h
> @@ -10,6 +10,8 @@
>
> #include <linux/mm.h>
>
> +#include <asm-generic/pgalloc.h> /* for pte_{alloc,free}_one */
> +
> #define pmd_populate_kernel(mm, pmd, pte) \
> set_pmd(pmd, __pmd(_PAGE_TABLE + (unsigned long) __pa(pte)))
>
> @@ -25,20 +27,6 @@
> extern pgd_t *pgd_alloc(struct mm_struct *);
> extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
>
> -extern pte_t *pte_alloc_one_kernel(struct mm_struct *);
> -extern pgtable_t pte_alloc_one(struct mm_struct *);
> -
> -static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
> -{
> - free_page((unsigned long) pte);
> -}
> -
> -static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
> -{
> - pgtable_page_dtor(pte);
> - __free_page(pte);
> -}
> -
> #define __pte_free_tlb(tlb,pte, address) \
> do { \
> pgtable_page_dtor(pte); \
> diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
> index 99aa11b..2280374 100644
> --- a/arch/um/kernel/mem.c
> +++ b/arch/um/kernel/mem.c
> @@ -215,28 +215,6 @@ void pgd_free(struct mm_struct *mm, pgd_t *pgd)
> free_page((unsigned long) pgd);
> }
>
> -pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
> -{
> - pte_t *pte;
> -
> - pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
> - return pte;
> -}
> -
> -pgtable_t pte_alloc_one(struct mm_struct *mm)
> -{
> - struct page *pte;
> -
> - pte = alloc_page(GFP_KERNEL|__GFP_ZERO);
> - if (!pte)
> - return NULL;
> - if (!pgtable_page_ctor(pte)) {
> - __free_page(pte);
> - return NULL;
> - }
> - return pte;
> -}
> -
> #ifdef CONFIG_3_LEVEL_PGTABLES
> pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
> {
>

Reviewed-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>

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Anton R. Ivanov
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