Messages in this thread | | | Subject | Re: [RFC][PATCH 0/3] New thermal interface allowing IPA to get max power | From | Lukasz Luba <> | Date | Mon, 1 Feb 2021 11:23:34 +0000 |
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Daniel, Chanwoo
Gentle ping. Have you have a chance to check these patches?
On 1/26/21 10:39 AM, Lukasz Luba wrote: > Hi all, > > This patch set tries to add the missing feature in the Intelligent Power > Allocation (IPA) governor which is: frequency limit set by user space. > User can set max allowed frequency for a given device which has impact on > max allowed power. In current design there is no mechanism to figure this > out. IPA must know the maximum allowed power for every device. It is then > used for proper power split and divvy-up. When the user limit for max > frequency is not know, IPA assumes it is the highest possible frequency. > It causes wrong power split across the devices. > > This new mechanism provides the max allowed frequency to the thermal > framework and then max allowed power to the IPA. > The implementation is done in this way because currently there is no way > to retrieve the limits from the PM QoS, without uncapping the local > thermal limit and reading the next value. It would be a heavy way of > doing these things, since it should be done every polling time (e.g. 50ms). > Also, the value stored in PM QoS can be different than the real OPP 'rate' > so still would need conversion into proper OPP for comparison with EM. > Furthermore, uncapping the device in thermal just to check the user freq > limit is not the safest way. > Thus, this simple implementation moves the calculation of the proper > frequency to the sysfs write code, since it's called less often. The value > is then used as-is in the thermal framework without any hassle. > > As it's a RFC, it still misses the cpufreq sysfs implementation, but would > be addressed if all agree. > > Regards, > Lukasz Luba > > Lukasz Luba (3): > PM /devfreq: add user frequency limits into devfreq struct > thermal: devfreq_cooling: add new callback to get user limit for min > state > thermal: power_allocator: get proper max power limited by user > > drivers/devfreq/devfreq.c | 41 ++++++++++++++++++++++++--- > drivers/thermal/devfreq_cooling.c | 33 +++++++++++++++++++++ > drivers/thermal/gov_power_allocator.c | 17 +++++++++-- > include/linux/devfreq.h | 4 +++ > include/linux/thermal.h | 1 + > 5 files changed, 90 insertions(+), 6 deletions(-) >
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