| Message ID | 13365827.uLZWGnKmhe@kreacher |
|---|---|
| Headers | show |
| Series | thermal: core: Pass trip pointers to governor .throttle() callbacks | expand |
Hi Rafael, On 10/6/23 18:38, Rafael J. Wysocki wrote: > Hi All, > > While working on https://lore.kernel.org/linux-pm/4846448.GXAFRqVoOG@kreacher/ > I started to change thermal governors so as to reduce the usage of trip > indices in them. At that time, I was concerned that they could not be > replaced with trip pointers overall, because they were needed in certain > situations (tracing, debug messages, userspace governor) and computing them > whenever they were needed would be extra overhead with relatively weak > justification. In the meantime, however, I realized that for a given trip > pointer, it is actually trivial to compute the corresponding index: it is > sufficient to subtract the start of the trips[] table in the thermal zone > containing the trip from that trip pointer for this purpose. Patch [1/6] > modifies thermal_zone_trip_id() in accordance with this observation. > > Now that the cost of computing a trip index for a given trip pointer and > thermal zone is not a concern any more, the governors can be generally > switched over to using trip pointers for representing trips. One of the > things they need to do sometimes, though, is to iterate over trips in a > given thermal zone (the core needs to do that too, of course) and > for_each_thermal_trip() is somewhat inconvenient for this purpose, because > it requires callback functions to be defined and in some cases new data > types need to be introduced just in order to use it. For this reason, > patch [2/6] adds a macro for iterating over trip points in a given thermal > zone with the help of a trip pointer and changes for_each_thermal_trip() to > use that macro internally. > > Patches [3-5/6] change individual governors to prepare them for using trip > pointers everywhere for representing trips, except for the trip argument of > the .throttle() callback and patch [6/6] finally changes the .throttle() > callback definition so that it takes a trip pointer as the argument > representing the trip. > > Please refer to the individual patch changelogs for details. > > Thanks! > > > I have issues to apply this series, could you tell me the best base branch from your tree? I will give it a try on my boards and review. Thanks, Lukasz
Hi Lukasz, On Fri, Oct 13, 2023 at 10:12 AM Lukasz Luba <lukasz.luba@arm.com> wrote: > > Hi Rafael, > > > On 10/6/23 18:38, Rafael J. Wysocki wrote: > > Hi All, > > > > While working on https://lore.kernel.org/linux-pm/4846448.GXAFRqVoOG@kreacher/ > > I started to change thermal governors so as to reduce the usage of trip > > indices in them. At that time, I was concerned that they could not be > > replaced with trip pointers overall, because they were needed in certain > > situations (tracing, debug messages, userspace governor) and computing them > > whenever they were needed would be extra overhead with relatively weak > > justification. In the meantime, however, I realized that for a given trip > > pointer, it is actually trivial to compute the corresponding index: it is > > sufficient to subtract the start of the trips[] table in the thermal zone > > containing the trip from that trip pointer for this purpose. Patch [1/6] > > modifies thermal_zone_trip_id() in accordance with this observation. > > > > Now that the cost of computing a trip index for a given trip pointer and > > thermal zone is not a concern any more, the governors can be generally > > switched over to using trip pointers for representing trips. One of the > > things they need to do sometimes, though, is to iterate over trips in a > > given thermal zone (the core needs to do that too, of course) and > > for_each_thermal_trip() is somewhat inconvenient for this purpose, because > > it requires callback functions to be defined and in some cases new data > > types need to be introduced just in order to use it. For this reason, > > patch [2/6] adds a macro for iterating over trip points in a given thermal > > zone with the help of a trip pointer and changes for_each_thermal_trip() to > > use that macro internally. > > > > Patches [3-5/6] change individual governors to prepare them for using trip > > pointers everywhere for representing trips, except for the trip argument of > > the .throttle() callback and patch [6/6] finally changes the .throttle() > > callback definition so that it takes a trip pointer as the argument > > representing the trip. > > > > Please refer to the individual patch changelogs for details. > > > > Thanks! > > > > > > > > I have issues to apply this series, could you tell me the best > base branch from your tree? > > I will give it a try on my boards and review. It is there in the thermal-core branch of linux-pm.git. Thanks!