Messages in this thread | | | Date | Mon, 29 Apr 2024 09:09:02 +0100 | Subject | Re: [PATCH v1] thermal: core: Move passive polling management to the core | From | Lukasz Luba <> |
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On 4/25/24 15:11, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Passive polling is enabled by setting the 'passive' field in > struct thermal_zone_device to a positive value so long as the > 'passive_delay_jiffies' field is greater than zero. It causes > the thermal core to actively check the thermal zone temperature > periodically which in theory should be done after crossing a > passive trip point on the way up in order to allow governors to > react more rapidly to temperature changes and adjust mitigation > more precisely. > > However, the 'passive' field in struct thermal_zone_device is currently > managed by governors which is quite problematic. First of all, only > two governors, Step-Wise and Power Allocator, update that field at > all, so the other governors do not benefit from passive polling, > although in principle they should. Moreover, if the zone governor is > changed from, say, Step-Wise to Fair-Share after 'passive' has been > incremented by the former, it is not going to be reset back to zero by > the latter even if the zone temperature falls down below all passive > trip points. > > For this reason, make handle_thermal_trip() increment 'passive' > to enable passive polling for the given thermal zone whenever a > passive trip point is crossed on the way up and decrement it > whenever a passive trip point is crossed on the way down. Also > remove the 'passive' field updates from governors and additionally > clear it in thermal_zone_device_init() to prevent passive polling > from being enabled after a system resume just beacuse it was enabled > before suspending the system. > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > > This has been mentioned here: > > https://lore.kernel.org/linux-pm/61560bc6-d453-4b0c-a4ea-b375d547b143@linaro.org/ > > and I need someone to double check if the Power Allocator governor does not > need to be adjusted more for this change.
I'll do this today (and the rest of the patch as well).
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