2018-05-02 07:55:37

by Ganesh Mahendran

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

Set ARCH_SUPPORTS_SPECULATIVE_PAGE_FAULT for arm64. This
enables Speculative Page Fault handler.

Signed-off-by: Ganesh Mahendran <[email protected]>
---
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

2018-05-02 12:23:46

by Will Deacon

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

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...

Will

>
> Signed-off-by: Ganesh Mahendran <[email protected]>
> ---
> 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
>

2018-05-04 06:07:22

by Ganesh Mahendran

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

2018-05-02 20:23 GMT+08:00 Will Deacon <[email protected]>:
> 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 <[email protected]>
>> ---
>> 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
>>