[Intel-gfx] [PATCH v3] drm/i915/perf: rate limit spurious oa report notice

[Matthew Auld]

On 04/05, Robert Bragg wrote:
> Instead of initializing and summarising the number of throttled messages in
> the driver _init / _fini we now do this when opening / closing an OA stream.
> 
> --- >8 ---
> 
> This change is pre-emptively aiming to avoid a potential cause of kernel
> logging noise in case some condition were to result in us seeing invalid
> OA reports.
> 
> The workaround for the OA unit's tail pointer race condition is what
> avoids the primary known cause of invalid reports being seen and with
> that in place we aren't expecting to see this notice but it can't be
> entirely ruled out.
> 
> Just in case some condition does lead to the notice then it's likely
> that it will be triggered repeatedly while attempting to append a
> sequence of reports and depending on the configured OA sampling
> frequency that might be a large number of repeat notices.
> 
> v2: (Chris) avoid inconsistent warning on throttle with
>     printk_ratelimit()
> v3: (Matt) init and summarise with stream init/close not driver init/fini
> 
> Signed-off-by: Robert Bragg <robert at sixbynine.org>
Reviewed-by: Matthew Auld <matthew.auld at intel.com>