Re: [LTP] [PATCH v3] thermal: add new test group

["Wysocki, Rafael J" <rafael.j.wysocki@intel.com>]

On 1/23/2026 7:28 PM, Petr Vorel wrote:
> Hi Piotr,
>
>>>> Then it
>>>> + * decreases the threshold for sending a thermal interrupt to just
>>>> above
>>>> + * the current temperature and runs a workload on the CPU.
>>> First, why test needs to run for 30 sec and then sleep for 10 sec?
> Maybe the most important of my questions / points.
>
>> Here the point is to use a decreasing timeout. The test starts with 10s
>> cooldown to make sure that even pre-production CPU's, which might have
>> their thermal protections disabled, cool down properly. Once sleep time
>> reaches 0, the conclusion is that either there was not enough workload
>> or somehow interrupts are not triggered after all.
> Why 30 sec and then sleep for 10 sec? Is it really needed to do it this way?

Of course not.


> Aren't these times depending on the tested machine? Some of them will fail due
> time not running enough,

That's unexpected with the numbers that are used, so something is amiss 
if it fails (and so it should fail).


> other will waste time (if they get interrupt e.g. in 10 sec).

That very well may happen, but is it a big deal?


> The usual approach would be to have the timeout safe enough for any type
> of hardware but proactively check the temperature and stop testing once it's
> done.

We want to create conditions in which the temperature should rise and if 
it doesn't, then there is a problem.

That said, the temperature can of course be checked more proactively, at 
least in principle, like say run cpu_workload() for 1s, check the 
temperature, repeat that several times, then cool down etc.

BR, Rafael



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