Re: [PATCH v4 6/7] PCI/AER: Add ratelimits to PCI AER Documentation

[Karolina Stolarek <karolina.stolarek@oracle.com>]

On 20/03/2025 09:20, Jon Pan-Doh wrote:
> Add ratelimits section for rationale and defaults.
> 
> Signed-off-by: Karolina Stolarek <karolina.stolarek@oracle.com>
> Signed-off-by: Jon Pan-Doh <pandoh@google.com>
> ---
>   Documentation/PCI/pcieaer-howto.rst | 11 +++++++++++
>   1 file changed, 11 insertions(+)
> 
> diff --git a/Documentation/PCI/pcieaer-howto.rst b/Documentation/PCI/pcieaer-howto.rst
> index f013f3b27c82..896d2a232a90 100644
> --- a/Documentation/PCI/pcieaer-howto.rst
> +++ b/Documentation/PCI/pcieaer-howto.rst
> @@ -85,6 +85,17 @@ In the example, 'Requester ID' means the ID of the device that sent
>   the error message to the Root Port. Please refer to PCIe specs for other
>   fields.
>   
> +AER Ratelimits
> +--------------
> +
> +Since error messages can be generated for each transaction, we may see
> +large volumes of errors reported. To prevent spammy devices from flooding
> +the console/stalling execution, messages are throttled by device and error
> +type (correctable vs. uncorrectable).
> +
> +AER uses the default ratelimit of DEFAULT_RATELIMIT_BURST (10 events) over
> +DEFAULT_RATELIMIT_INTERVAL (5 seconds).

This is not quite true, as we double the number of available bursts so 
we can print both the port info and an error message. We could say that 
this limit (2 * DEFAULT_RATELIMIT_BURST) roughly translates to ten error 
notifications within the 5 second window.

All the best,
Karolina