linux-kernel - Re: [PATCH 13/15] riscv: switch to generic version of pte allocation

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Date:   Mon, 06 May 2019 11:25:52 -0700 (PDT)
From:   Palmer Dabbelt <palmer@...ive.com>
To:     rppt@...ux.ibm.com
CC:     akpm@...ux-foundation.org, Arnd Bergmann <arnd@...db.de>,
        catalin.marinas@....com, geert@...ux-m68k.org, green.hu@...il.com,
        gxt@....edu.cn, guoren@...nel.org, deller@....de, lftan@...era.com,
        willy@...radead.org, mattst88@...il.com, mpe@...erman.id.au,
        mhocko@...e.com, paul.burton@...s.com, rkuo@...eaurora.org,
        richard@....at, linux@...linux.org.uk, sammy@...my.net,
        x86@...nel.org, linux-alpha@...r.kernel.org,
        linux-arch@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-hexagon@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-m68k@...ts.linux-m68k.org, linux-mips@...r.kernel.org,
        linux-parisc@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
        linux-riscv@...ts.infradead.org, linux-um@...ts.infradead.org,
        nios2-dev@...ts.rocketboards.org, rppt@...ux.ibm.com
Subject:     Re: [PATCH 13/15] riscv: switch to generic version of pte allocation

On Thu, 02 May 2019 08:28:40 PDT (-0700), rppt@...ux.ibm.com wrote:
> The only difference between the generic and RISC-V implementation of PTE
> allocation is the usage of __GFP_RETRY_MAYFAIL for both kernel and user
> PTEs and the absence of __GFP_ACCOUNT for the user PTEs.
>
> The conversion to the generic version removes the __GFP_RETRY_MAYFAIL and
> ensures that GFP_ACCOUNT is used for the user PTE allocations.

Reviewed-by: Palmer Dabbelt <palmer@...ive.com>

I'm assuming this is going in along with the rest of the patches, so I'm not
going to add it to my tree.

>
> 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@...ux.ibm.com>
> ---
>  arch/riscv/include/asm/pgalloc.h | 29 ++---------------------------
>  1 file changed, 2 insertions(+), 27 deletions(-)
>
> diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h
> index 94043cf..48f28bb 100644
> --- a/arch/riscv/include/asm/pgalloc.h
> +++ b/arch/riscv/include/asm/pgalloc.h
> @@ -18,6 +18,8 @@
>  #include <linux/mm.h>
>  #include <asm/tlb.h>
>
> +#include <asm-generic/pgalloc.h>	/* for pte_{alloc,free}_one */
> +
>  static inline void pmd_populate_kernel(struct mm_struct *mm,
>  	pmd_t *pmd, pte_t *pte)
>  {
> @@ -82,33 +84,6 @@ static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
>
>  #endif /* __PAGETABLE_PMD_FOLDED */
>
> -static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
> -{
> -	return (pte_t *)__get_free_page(
> -		GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_ZERO);
> -}
> -
> -static inline struct page *pte_alloc_one(struct mm_struct *mm)
> -{
> -	struct page *pte;
> -
> -	pte = alloc_page(GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_ZERO);
> -	if (likely(pte != NULL))
> -		pgtable_page_ctor(pte);
> -	return pte;
> -}
> -
> -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, buf)   \
>  do {                                    \
>  	pgtable_page_dtor(pte);         \