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Subject: Re: [v2 1/1] x86/cpufeatures: Implement Predictive Store Forwarding
 control.
To:     Randy Dunlap <rdunlap@infradead.org>, linux-kernel@vger.kernel.org,
        x86@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        hpa@zytor.com, Jonathan Corbet <corbet@lwn.net>
Cc:     bsd@redhat.com
References: <20210422171013.50207-1-rsaripal@amd.com>
 <20210422171013.50207-2-rsaripal@amd.com>
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From:   "Saripalli, RK" <rsaripal@amd.com>
Message-ID: <6813af1c-6a59-47ca-ce40-939512092b09@amd.com>
Date:   Thu, 22 Apr 2021 14:32:56 -0500
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On 4/22/2021 12:49 PM, Randy Dunlap wrote:
> On 4/22/21 10:10 AM, Ramakrishna Saripalli wrote:
>> From: Ramakrishna Saripalli <rk.saripalli@amd.com>
>>
>> ====================
>> Signed-off-by: Ramakrishna Saripalli<rk.saripalli@amd.com>
>> ---
>>  .../admin-guide/kernel-parameters.txt         |  5 +++++
>>  arch/x86/include/asm/cpufeatures.h            |  1 +
>>  arch/x86/include/asm/msr-index.h              |  2 ++
>>  arch/x86/kernel/cpu/amd.c                     | 19 +++++++++++++++++++
>>  4 files changed, 27 insertions(+)
> 
> as from v1:

Randy, could you clarify your comments please?. Is there something here I need to change/clarify/fix?

> 
>> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
>> index 04545725f187..58f6bd02385b 100644
>> --- a/Documentation/admin-guide/kernel-parameters.txt
>> +++ b/Documentation/admin-guide/kernel-parameters.txt
>> @@ -3940,6 +3940,11 @@
>>  			Format: {"off"}
>>  			Disable Hardware Transactional Memory
>>  
>> +	predict_store_fwd	[X86] This option controls PSF mitigation
> 
> 	predict_store_fwd=	...
> 

OK

>> +			off - Turns on PSF mitigation.
>> +			on  - Turns off PSF mitigation.
>> +			default : on.
> 
> 			default: on.
> 

OK

>> +
>>  	preempt=	[KNL]
>>  			Select preemption mode if you have CONFIG_PREEMPT_DYNAMIC
>>  			none - Limited to cond_resched() calls
> thanks.
>