Re: RFC: Counters for PCI Express AERs

[okaya@codeaurora.org]

On 2018-05-17 17:05, Rajat Jain wrote:
> Hello,
> 
> I have been thinking about adding counters for different kinds of AERs
> and expose them via sysfs. IMHO this would help by giving some sense
> of "link quality" for PCIe links (a lot of correctable AERs may
> indicate system is workable, but may indicate some signal integrity
> issues etc). Currently, on a correctable AER, we do log them, but
> having them in sysfs would allow userspace tools to possibly
> (periodically) poll them and raise an appropriate warning in case of
> too many errors. I know that for my purposes, getting some idea of PCI
> link quality or a way to quantize it, would help.
> 
> Do you think such counters make sense or would be helpful generically?
> Also, please let me know if something like this already exists?

This question came from FB folks last year. They were told to use the 
perf events for counting.

I don't honestly have a strong opinion.

> 
> Thanks,
> 
> Rajat