Re: [PATCH v7 1/2] cpufreq: Remove per-CPU QoS constraint

[Viresh Kumar]

What do you mean by per-CPU QOS constraint in Subject ? This is per-policy
constraint and you are not removing it, you are just avoiding to update it in
one of the paths.

On 25-03-26, 17:52, Pierre Gondois wrote:
> policy->max_freq_req QoS constraint represents the maximal allowed
> frequency than can be requested. It is set by:
> - writing to policyX/scaling_max sysfs file
> - toggling the cpufreq/boost sysfs file
> 
> Upon calling freq_qos_update_request(), a successful update
> of the max_freq_req value triggers cpufreq_notifier_max(),
> followed by cpufreq_set_policy() which update the requested
> frequency for the policy.
> If the new max_freq_req value is not different from the
> original value, no frequency update is triggered.
> 
> In a specific sequence of toggling:
> - cpufreq/boost sysfs file
> - CPU hot-plugging
> a CPU could end up with boost enabled but running at the
> maximal non-boost frequency, cpufreq_notifier_max() not being
> triggered. The following fixed that:
> commit 1608f0230510 ("cpufreq: Fix re-boost issue after hotplugging
> a CPU")
> 
> The following:
> commit dd016f379ebc ("cpufreq: Introduce a more generic way to
> set default per-policy boost flag")
> also fixed the issue by correctly setting the max_freq_req
> constraint of a policy that is re-activated. This makes the
> first fix unnecessary.
> 
> As the original issue is fixed by another method,
> this patch reverts:
> commit 1608f0230510 ("cpufreq: Fix re-boost issue after hotplugging
> a CPU")

Looks okay otherwise.

-- 
viresh