From: Bandan Das <bsd@redhat.com>
To: Randy Dunlap <rdunlap@infradead.org>
Cc: Ramakrishna Saripalli <rsaripal@amd.com>,
linux-kernel@vger.kernel.org, x86@kernel.org, tglx@linutronix.de,
mingo@redhat.com, bp@alien8.de, Jonathan Corbet <corbet@lwn.net>
Subject: Re: [PATCH 4/4] x86/speculation: Add PSF mitigation kernel parameters
Date: Wed, 21 Apr 2021 14:32:13 -0400 [thread overview]
Message-ID: <jpg4kfzfpzm.fsf@linux.bootlegged.copy> (raw)
In-Reply-To: <4c688fc7-67df-3187-54b2-bf20e510fb39@infradead.org> (Randy Dunlap's message of "Wed, 21 Apr 2021 09:04:30 -0700")
Randy Dunlap <rdunlap@infradead.org> writes:
> Hi,
>
> On 4/21/21 2:01 AM, Ramakrishna Saripalli wrote:
>> From: Ramakrishna Saripalli <rk.saripalli@amd.com>
>>
>> PSF mitigation introduces a new kernel parameter called
>> predict_store_fwd.
>>
>> Signed-off-by: Ramakrishna Saripalli<rk.saripalli@amd.com>
>> ---
>> Documentation/admin-guide/kernel-parameters.txt | 5 +++++
>> 1 file changed, 5 insertions(+)
>>
>> 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
>> + off - Turns on PSF mitigation.
>> + on - Turns off PSF mitigation.
>> + default : on.
>
> This should be formatted more like:
>
> + predict_store_fwd= [X86] This option controls PSF mitigation
> + off - Turns on PSF mitigation.
> + on - Turns off PSF mitigation.
> + default: on.
>
> But why does "off" turn it on and "on" turn it off?
>
Maybe, rename the parameter to something like psfd_disable, then off -> disables mitigation and on -> enables it.
Or just rewriting this to off -> turns off predictive store forwarding is probably ok too.
Bandan
>
>> +
>> preempt= [KNL]
>> Select preemption mode if you have CONFIG_PREEMPT_DYNAMIC
>> none - Limited to cond_resched() calls
>>
>
> thanks.
next prev parent reply other threads:[~2021-04-21 18:34 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-21 9:01 [PATCH 0/4] Introduce support for PSF mitigation Ramakrishna Saripalli
2021-04-21 9:01 ` [PATCH 1/4] x86/cpufeatures: Define feature bits to support mitigation of PSF Ramakrishna Saripalli
2021-04-21 9:01 ` [PATCH 2/4] x86/speculation: Introduce SPEC_CTRL_MSR bit for PSFD Ramakrishna Saripalli
2021-04-21 9:01 ` [PATCH 3/4] x86/speculation: Implement PSF mitigation support Ramakrishna Saripalli
2021-04-21 9:01 ` [PATCH 4/4] x86/speculation: Add PSF mitigation kernel parameters Ramakrishna Saripalli
2021-04-21 16:04 ` Randy Dunlap
2021-04-21 18:32 ` Bandan Das [this message]
2021-04-21 18:36 ` Saripalli, RK
2021-04-21 18:48 ` Borislav Petkov
2021-04-21 18:55 ` Saripalli, RK
2021-04-21 18:57 ` Borislav Petkov
2021-04-21 19:05 ` Saripalli, RK
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