Messages in this thread | | | Date | Tue, 30 Apr 2024 17:47:10 +0100 | Subject | Re: [PATCH v2 2/2] thermal: core: Move passive polling management to the core | From | Lukasz Luba <> |
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On 4/30/24 16:52, 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> > --- > > v1 -> v2: > * Add a WARN_ON() check for tz->passive < 0. > * Do not start passive polling until tz->passive is positive. > > --- > drivers/thermal/gov_power_allocator.c | 12 +++++++----- > drivers/thermal/gov_step_wise.c | 10 ---------- > drivers/thermal/thermal_core.c | 14 +++++++++++--- > 3 files changed, 18 insertions(+), 18 deletions(-) >
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
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