Re: [PATCH v6 1/4] cpufreq: Remove per-CPU QoS constraint

["zhenglifeng (A)" <zhenglifeng1@huawei.com>]

On 3/19/2026 5:30 PM, Pierre Gondois wrote:
> 
> On 3/18/26 12:13, Viresh Kumar wrote:
>> On 17-03-26, 11:17, Pierre Gondois wrote:
>>> policy->max_freq_req represents the maximum allowed frequency as
>>> requested by the policyX/scaling_max_freq sysfs file. This request
>>> applies to all CPUs of the policy. It is not possible to request
>>> a per-CPU maximum frequency.
>>>
>>> Thus, the interaction between the policy boost and scaling_max_freq
>>> settings should be handled by adding a boost specific QoS constraint.
>>> This will be handled in the following patches.
>> I don't think the above is required anymore. This patch is removing stale code
>> now which isn't useful anymore. It has nothing to do with a boost specific QOS
>> constraint.
> Yes ok
>> And it would be better to know for sure why this isn't required anymore and
>> which patch exactly fixed this issue.
>>
> On a kernel based on 1608f0230510~, and replicating the
> process described in the commit message of
> 
> commit 1608f0230510 ("cpufreq: Fix re-boost issue after hotplugging
> a CPU")
> 
> I could not see any issue regarding the values of:
> 
> - policy1/cpuinfo_max_freq
> - policy1/scaling_max_freq
> 
> The following sequence however had an issue:
> 
> 1. echo 0 > /sys/devices/system/cpu/cpu1/online
> 2. echo 1 > /sys/devices/system/cpu/cpufreq/boost
> 3. echo 1 > /sys/devices/system/cpu/cpu1/online
> 
> as after 1.:
> 
> cpufreq_boost_trigger_state()
> \-for_each_active_policy()
> 
> doesn't enable boost for inactive policies. This leads to
> CPU1 having the non-boosted frequency as its max freq.
> 
> The above sequence is fixed by:
> 
> commit a153c6049ab8 ("cpufreq: Introduce a more
> generic way to set default per-policy boost flag")

Yes, I think this commit fixed the issue but I didn't realize it before so
I sent them both. 😂

> 
> ---
> 
> @Lifeng, should I check something else than the value of:
> 
> - policy1/cpuinfo_max_freq
> - policy1/scaling_max_freq
> 
> in order to reproduce the issue fixed by:
> 
> commit 1608f0230510 ("cpufreq: Fix re-boost issue after hotplugging
> a CPU")
> 
> ?
> 
> 
>