Re: [PATCH v10 05/10] arm64/vmalloc: allow arch_vmap_pte_range_map_size() to batch multiple CONT_PTE

[Uladzislau Rezki <urezki@gmail.com>]

On Fri, Oct 02, 2026 at 05:09:42PM +0800, Wen Jiang wrote:
> From: "Barry Song (Xiaomi)" <baohua@kernel.org>
> 
> Allow arch_vmap_pte_range_map_size to batch across multiple CONT_PTE
> blocks, reducing both PTE setup and TLB flush iterations.
> 
> Previously the function returned a single CONT_PTE_SIZE for an aligned
> range, so the caller mapped one CONT_PTE block per iteration. Now, for a
> CONT_PTE_SIZE-aligned range, it returns the largest CONT_PTE-aligned size
> that fits within both the remaining range and the caller's max_page_shift,
> so a single pte_set_huge() call installs several CONT_PTE blocks at once.
> 
> Signed-off-by: Barry Song (Xiaomi) <baohua@kernel.org>
> Signed-off-by: Wen Jiang <jiangwen6@xiaomi.com>
> Tested-by: Xueyuan Chen <xueyuan.chen21@gmail.com>
> Tested-by: Leo Yan <leo.yan@arm.com>
> ---
>  arch/arm64/include/asm/vmalloc.h | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/vmalloc.h b/arch/arm64/include/asm/vmalloc.h
> index 4ec1acd3c1b34..c29704a19e276 100644
> --- a/arch/arm64/include/asm/vmalloc.h
> +++ b/arch/arm64/include/asm/vmalloc.h
> @@ -23,10 +23,12 @@ static inline unsigned long arch_vmap_pte_range_map_size(unsigned long addr,
>  						unsigned long end, u64 pfn,
>  						unsigned int max_page_shift)
>  {
> +	unsigned long size;
> +
>  	/*
> -	 * If the block is at least CONT_PTE_SIZE in size, and is naturally
> -	 * aligned in both virtual and physical space, then we can pte-map the
> -	 * block using the PTE_CONT bit for more efficient use of the TLB.
> +	 * If the range is at least CONT_PTE_SIZE and naturally aligned in both
> +	 * virtual and physical space, return the largest CONT_PTE-aligned size
> +	 * that fits, for more efficient use of the TLB.
>  	 */
>  	if (max_page_shift < CONT_PTE_SHIFT)
>  		return PAGE_SIZE;
> @@ -40,7 +42,9 @@ static inline unsigned long arch_vmap_pte_range_map_size(unsigned long addr,
>  	if (!IS_ALIGNED(PFN_PHYS(pfn), CONT_PTE_SIZE))
>  		return PAGE_SIZE;
>  
> -	return CONT_PTE_SIZE;
> +	size = min(end - addr, 1UL << max_page_shift);
> +	size = round_down(size, CONT_PTE_SIZE);
> +	return size;
>  }
>  
>  #define arch_vmap_pte_range_unmap_size arch_vmap_pte_range_unmap_size
> -- 
> 2.34.1
> 
This is arch/arm64 code. Can you, Jain or Ryan from ARM folk review this change?

Thank you!

--
Uladzislau Rezki