Re: 答复: 答复: 答复: [外部邮件] Re: [PATCH] x86/mce: Fix timer interval adjustment after logging a MCE event

[Nikolay Borisov <nik.borisov@suse.com>]

On 13.01.26 г. 20:53 ч., Luck, Tony wrote:
>>> The comment in mce_timer_fn says to adjust the polling interval, but
>>> I notice the kernel log always shows an MCE log every 5 minutes. Is this
>>> normal?
>>
>> Use git annotate to figure out which patch added this comment and in context
>> of what and that'll tell you why.
>>
>> As to the 5 minutes, look at how the check interval gets established.
> 
> Once upon a time the polling interval started out at 5 minutes, but the
> interval was halved each time an error was found (so interval went
> 150s, 75s, 37s, ... down to 1s). If no error was found, then the interval
> was doubled (going back up to 300s).
> 
> This is described in the comment:
> 
>          /*
>           * Alert userspace if needed. If we logged an MCE, reduce the polling
>           * interval, otherwise increase the polling interval.
>           */
> 
> It seems that the kernel isn't doing that today. Polling at a fixed 300 seconds
> event though errors are being found and logged. Interesting that the timestamps
> are 327.68 seconds apart, rather than 300 and change. So there is some strange
> stuff going on.

I think Li Rongqing patch does exactly that, since it predicates the 
halving/doubling of the interval based on whether an error was found and 
not whether it was reported to user space (what mce_notify_irq() ) does. 
Both concepts seems to be independent and the former being the core one 
we care about w.r.t to the decision how to adjust the interval, no ?

<snip>