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

[Dev Jain <dev.jain@arm.com>]

On 11/10/26 3:15 pm, Uladzislau Rezki wrote:
> 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!
> 

I will come to this soon.


> --
> Uladzislau Rezki