Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [v2 1/1] x86/cpufeatures: Implement Predictive Store Forwarding
 control.
To:     "Saripalli, RK" <rsaripal@amd.com>, 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>
 <ee949efc-018c-8b70-3224-da4f24b217b6@infradead.org>
 <6813af1c-6a59-47ca-ce40-939512092b09@amd.com>
From:   Randy Dunlap <rdunlap@infradead.org>
Message-ID: <6e755a24-1309-e75a-175c-196951f1167c@infradead.org>
Date:   Thu, 22 Apr 2021 13:46:40 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.8.0
MIME-Version: 1.0
In-Reply-To: <6813af1c-6a59-47ca-ce40-939512092b09@amd.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 4/22/21 12:32 PM, Saripalli, RK wrote:
> 
> 
> 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?
> 

Only that I had made these same comments (below)
in v1 of the patch.

https://lore.kernel.org/lkml/4c688fc7-67df-3187-54b2-bf20e510fb39@infradead.org/

>>
>>> 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

-- 
~Randy