Re: [PATCH 1/2] x86, mce, therm_throt: Optimize logging of thermal throttle messages

From: Peter Zijlstra
Date: Tue Oct 15 2019 - 04:48:46 EST

On Mon, Oct 14, 2019 at 02:21:00PM -0700, Srinivas Pandruvada wrote:
> Some modern systems have very tight thermal tolerances. Because of this
> they may cross thermal thresholds when running normal workloads (even
> during boot). The CPU hardware will react by limiting power/frequency
> and using duty cycles to bring the temperature back into normal range.
> Thus users may see a "critical" message about the "temperature above
> threshold" which is soon followed by "temperature/speed normal". These
> messages are rate limited, but still may repeat every few minutes.
> The solution here is to set a timeout when the temperature first exceeds
> the threshold.

Why can we even reach critical thresholds when the fans are working? I
always thought it was BAD to ever reach the critical temps and have the
hardware throttle.