Re: [PATCH 1/2] arm64/mm: define ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT

From: Ganesh Mahendran
Date: Fri May 04 2018 - 02:05:36 EST


2018-05-02 20:23 GMT+08:00 Will Deacon <will.deacon@xxxxxxx>:
> On Wed, May 02, 2018 at 03:53:21PM +0800, Ganesh Mahendran wrote:
>> Set ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT for arm64. This
>> enables Speculative Page Fault handler.
>
> Are there are tests for this? I'm really nervous about enabling it...

Hi, Will

I test the arm64 spf on Qcom SDM845 cpu with kernel 4.9.
It looks good for performance, and have not found stability issue yet.

Thanks.

>
> Will
>
>>
>> Signed-off-by: Ganesh Mahendran <opensource.ganesh@xxxxxxxxx>
>> ---
>> This patch is on top of Laurent's v10 spf
>> ---
>> arch/arm64/Kconfig | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>> index eb2cf49..cd583a9 100644
>> --- a/arch/arm64/Kconfig
>> +++ b/arch/arm64/Kconfig
>> @@ -144,6 +144,7 @@ config ARM64
>> select SPARSE_IRQ
>> select SYSCTL_EXCEPTION_TRACE
>> select THREAD_INFO_IN_TASK
>> + select ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT if SMP
>> help
>> ARM 64-bit (AArch64) Linux support.
>>
>> --
>> 1.9.1
>>