Re: [PATCH -tip 1/3] x86, mce: Add mce_threshold option for intel cmci

[Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>]

Hi Ingo,

Sorry, could you drop patch 1/3 and 3/3 from your -tip tree?
Andi and I discussed some and agreed disabling CMCI need to be
done in different way (at least parameter name).

Thanks,
H.Seto

Ingo Molnar wrote:
> * Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> wrote:
> 
>> This patch adds a kernel parameter "mce_threshold=n" to enable us
>> to change the default threshold for CMCI(Corrected Machine Check
>> Interrupt) that recent Intel processor supports.
>>
>> And it also supports CMCI disabling by setting mce_threshold=0.
>> It would be useful if your hardware does something wrong and/or
>> if polling by timer is preferred than the threshold interrupt.
>>
>> Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
>> Cc: Andi Kleen <ak@linux.intel.com>
>> Cc: Ingo Molnar <mingo@elte.hu>
>> ---
>>  Documentation/kernel-parameters.txt       |    5 +++
>>  arch/x86/include/asm/msr-index.h          |    1 +
>>  arch/x86/kernel/cpu/mcheck/mce_intel_64.c |   56 +++++++++++++++++++++++++++--
>>  3 files changed, 59 insertions(+), 3 deletions(-)
>>
>> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
>> index 1d8af36..7a0d117 100644
>> --- a/Documentation/kernel-parameters.txt
>> +++ b/Documentation/kernel-parameters.txt
>> @@ -1267,6 +1267,11 @@ and is between 256 and 4096 characters. It is defined in the file
>>  
>>  	mce=option	[X86-64] See Documentation/x86/x86_64/boot-options.txt
>>  
>> +	mce_threshold=	[X86-64,intel] Default CMCI threshold
>> +			Should be unsigned integer. Setting 0 disables cmci.
>> +			Format: <integer>
>> +			Default: 1
> 
> Makes sense. CMCI is a new CPU feature so having boot controls to 
> disable it is generally a good idea - while still having old-style 
> MCE support in place.
> 
> Applied to tip:x86/mce2, thanks Hidetoshi!
> 
> 	Ingo
> 
>