linux-kernel - Re: [RESEND][PATCH -tip 3/3] x86, mce: Add new option mce=no_cmci and mce=ignore

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Message-ID: <49EC3AC0.8070109@jp.fujitsu.com>
Date:	Mon, 20 Apr 2009 18:05:04 +0900
From:	Hidetoshi Seto <seto.hidetoshi@...fujitsu.com>
To:	Andi Kleen <andi@...stfloor.org>
CC:	linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...e.hu>,
	Andi Kleen <ak@...ux.intel.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [RESEND][PATCH -tip 3/3] x86, mce: Add new option mce=no_cmci
 and mce=ignore_ce

Andi Kleen wrote:
> Hidetoshi Seto <seto.hidetoshi@...fujitsu.com> writes:
> 
>> This patch introduces a couple of boot option for x86_64 mce.
>>
>> The "mce=no_cmci" boot option disables cmci feature.
>> Since cmci is a new feature so having boot controls to disable
>> it will be a help if the hardware is misbehaving.
> 
> Acked-by: Andi Kleen <ak@...ux.intel.com>
> 
> Although I expect on Nehalem you'll get more problems without CMCI
> than with due to the shared banks. Perhaps the documentation
> should make that clearer.

Good idea.  I'll add it to boot-options.txt

>> The "mce=ignore_ce" boot option disables features for corrected
>> errors, i.e. polling timer and cmci.  Usually this disablement
>> is not recommended, however it will be a help if there are some
>> conflict with the BIOS or hardware monitoring applications etc.
> 
> Same problem as with the earlier patch.  You need a point
> somewhere where the event is cleared, otherwise all hell
> breaks loose.

Adding "dont_log_ce" and its description will be a help.
It need to describe how it different from ignore_ce and how events
are cleared.

>>  static int mce_dont_init;
>> +int cmci_disabled;
>> +int ignore_ce;
> 
> For global variables you should use a mce_ prefix to not pollute
> global name space.

OK.  I'll fix.

>> diff --git a/arch/x86/kernel/cpu/mcheck/mce_intel_64.c b/arch/x86/kernel/cpu/mcheck/mce_intel_64.c
>> index d6b72df..64c0dd9 100644
>> --- a/arch/x86/kernel/cpu/mcheck/mce_intel_64.c
>> +++ b/arch/x86/kernel/cpu/mcheck/mce_intel_64.c
>> @@ -109,6 +109,9 @@ static int cmci_supported(int *banks)
>>  {
>>  	u64 cap;
>>  
>> +	if (cmci_disabled | ignore_ce)
> 
> I presume you meant || here

Yes, should be fixed.


Thanks,
H.Seto

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