[PATCH v1 0/5] cpuidle: Take possible negative "sleep length" values into account

[Rafael J. Wysocki]

Hi All,

As follows from the discussion triggered by the patch at

https://lore.kernel.org/lkml/20210311123708.23501-2-frederic@xxxxxxxxxx/

the cpuidle governors using tick_nohz_get_sleep_length() assume it to always
return positive values which is not correct in general.

To address this issues, first document the fact that negative values can
be returned by tick_nohz_get_sleep_length() (patch [1/5]).  Then, in
preparation for more substantial changes, change the data type of two
fields in struct cpuidle_state to s64 so they can be used in computations
involving negative numbers safely (patch [2/5]).

Next, adjust the teo governor a bit so that negative "sleep length" values
are counted like zero by it (patch [3/5]) and modify it so as to avoid
mishandling negative "sleep length" values (patch [4/5]).

Finally, make the menu governor take negative "sleep length" values into
account properly (patch [5/5]).

Please see the changelogs of the patches for details.

Thanks!