linux-kernel - Re: [PATCH 1/3] thermal: power_allocator: respect upper and lower bounds for cooling device

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <b280a851-a4ea-490e-8cee-327bc34ee8b9@arm.com>
Date:   Wed, 14 Oct 2020 17:05:56 +0100
From:   Lukasz Luba <lukasz.luba@....com>
To:     Daniel Lezcano <daniel.lezcano@...aro.org>
Cc:     linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        amitk@...nel.org, Dietmar.Eggemann@....com,
        michael.kao@...iatek.com, rui.zhang@...el.com
Subject: Re: [PATCH 1/3] thermal: power_allocator: respect upper and lower
 bounds for cooling device



On 10/14/20 1:31 PM, Daniel Lezcano wrote:
> On 07/10/2020 14:22, Lukasz Luba wrote:
>> The thermal cooling device specified in DT might be instantiated for
>> a thermal zone trip point with a limited set of OPPs to operate on. This
>> configuration should be supported by Intelligent Power Allocation (IPA),
>> since it is a standard for other governors. Change the code and allow IPA
>> to get power value of lower and upper bound set for a given cooling
>> device.
>>
>> Signed-off-by: Lukasz Luba <lukasz.luba@....com>
>> ---
>>   drivers/thermal/gov_power_allocator.c | 6 ++++--
>>   1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c
>> index dd59085f38f5..f9ee7787b325 100644
>> --- a/drivers/thermal/gov_power_allocator.c
>> +++ b/drivers/thermal/gov_power_allocator.c
>> @@ -96,7 +96,8 @@ static u32 estimate_sustainable_power(struct thermal_zone_device *tz)
>>   		if (instance->trip != params->trip_max_desired_temperature)
>>   			continue;
>>   
>> -		if (power_actor_get_min_power(cdev, tz, &min_power))
>> +		if (cdev->ops->state2power(cdev, tz, instance->upper,
>> +					   &min_power))
> 
> 	if (cdev->ops->state2power && cdev->ops->state2power(cdev, tz,
> 							instance->upper,
> 							&min_power))
> 
> ?


Yes, worth to check. I had this in [1] and missed it here while playing
with re-base of these patch series and other test branches.

I will send v2 with the needed cdev_is_power_actor() check.

> 
>>   			continue;
>>   
>>   		sustainable_power += min_power;
>> @@ -404,7 +405,8 @@ static int allocate_power(struct thermal_zone_device *tz,
>>   
>>   		weighted_req_power[i] = frac_to_int(weight * req_power[i]);
>>   
>> -		if (power_actor_get_max_power(cdev, tz, &max_power[i]))
>> +		if (cdev->ops->state2power(cdev, tz, instance->lower,
>> +					   &max_power[i]))
>>   			continue;
> 
> Same here ?

Inside that loop we check (just a few lines above):

		if (!cdev_is_power_actor(cdev))
			continue;

then we call this:

		if (cdev->ops->state2power(cdev, tz, instance->lower,
					&max_power[i]))

So it should be safe.

> 
>>   		total_req_power += req_power[i];
>>
> 
> 

Thank you Daniel for reviewing this.

Regards,
Lukasz

[1] 
https://lore.kernel.org/linux-pm/20201008170426.465-3-lukasz.luba@arm.com/