Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Fri, 30 Jun 2023 12:46:24 +0200 | Subject | Re: [PATCH 1/1] thermal: sysfs: avoid actual readings from sysfs |
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Hi Daniel,
On Fri, Jun 30, 2023 at 12:11 PM Daniel Lezcano <daniel.lezcano@linaro.org> wrote: > > > Hi Rafael, > > On 30/06/2023 10:16, Rafael J. Wysocki wrote: > > On Wed, Jun 28, 2023 at 11:10 PM Eduardo Valentin <evalenti@kernel.org> wrote: > > [ ... ] > > > So what about adding a new zone attribute that can be used to specify > > the preferred caching time for the temperature? > > > > That is, if the time interval between two consecutive updates of the > > cached temperature value is less than the value of the new attribute, > > the cached temperature value will be returned by "temp". Otherwise, > > it will cause the sensor to be read and the value obtained from it > > will be returned to user space and cached. > > > > If the value of the new attribute is 0, everything will work as it > > does now (which will also need to be the default behavior). > > I'm still not convinced about the feature. > > Eduardo provided some numbers but they seem based on the characteristics > of the I2C, not to a real use case. Eduardo? > > Before adding more complexity in the thermal framework and yet another > sysfs entry, it would be interesting to have an experiment and show the > impact of both configurations, not from a timing point of view but with > a temperature mitigation accuracy. > > Without a real use case, this feature does make really sense IMO.
I'm kind of unsure why you think that it is not a good idea in general to have a way to limit the rate of accessing a temperature sensor, for energy-efficiency reasons if nothing more.
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