linux-kernel - Re: [PATCH v2 3/3] x86/mce: Make mce_notify_irq() depend on CONFIG_X86_MCELOG

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Message-ID: <9c44d283-60d1-4bc9-bfa3-425a8155cca9@suse.com>
Date: Tue, 11 Feb 2025 12:18:23 +0200
From: Nikolay Borisov <nik.borisov@...e.com>
To: "Zhuo, Qiuxu" <qiuxu.zhuo@...el.com>,
 "linux-edac@...r.kernel.org" <linux-edac@...r.kernel.org>
Cc: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
 "x86@...nel.org" <x86@...nel.org>, "Luck, Tony" <tony.luck@...el.com>
Subject: Re: [PATCH v2 3/3] x86/mce: Make mce_notify_irq() depend on
 CONFIG_X86_MCELOG_LEGACY



On 11.02.25 г. 9:20 ч., Zhuo, Qiuxu wrote:
>> From: Nikolay Borisov <nik.borisov@...e.com>
>> [...]
>> Subject: [PATCH v2 3/3] x86/mce: Make mce_notify_irq() depend on
>> CONFIG_X86_MCELOG_LEGACY
>>
>> mce_notify_irq() really depends on the legacy mcelog being enabled as
>> otherwise mce_work_trigger() will never schedule the trigger work as
>> mce_helper can't be set unless CONFIG_X86_MCELOG_LEGACY is defined.
>>
>> Signed-off-by: Nikolay Borisov <nik.borisov@...e.com>
>> ---
>>   arch/x86/kernel/cpu/mce/core.c | 4 +++-
>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
>> index d55b1903fde6..8b8553e144ce 100644
>> --- a/arch/x86/kernel/cpu/mce/core.c
>> +++ b/arch/x86/kernel/cpu/mce/core.c
>> @@ -591,11 +591,13 @@ EXPORT_SYMBOL_GPL(mce_is_correctable);
>>    */
>>   static int mce_notify_irq(void)
>>   {
>> +#ifdef CONFIG_X86_MCELOG_LEGACY
>> +
>>   	if (test_and_clear_bit(0, &mce_need_notify)) {
>>   		mce_work_trigger();
>>   		return 1;
>>   	}
>> -
>> +#endif
>>   	return 0;
>>   }
> 
> The empty stub function below can also be removed from the file: arch/x86/kernel/cpu/mce/internal.h
> 
>           static inline void mce_work_trigger(void)       { }


Actually I think this patch is better off being dropped. With it 
mce_notify_irq will always return false, causing mce_timer_fn() to 
always increase the polling interval until it stabilizes at around 
check_interval.

I will wait a bit for some more feedback and will repost v3 which will 
consist of only patches 1 and 2.