On Wed, Sep 10, 2014 at 8:59 PM, <Valdis.Kletnieks@xxxxxx> wrote: > On Wed, 10 Sep 2014 20:26:48 +0300, Ran Shalit said: > >> What is usually the criterion for PM (power management) suspending >> that application shall use ? Is it according to minimum threshold for >> cpu load (as indication for no process) ? > > That will be highly application dependent. Something that checks your email > in the background may not care at all, as long as it gets network > access every 5 minutes or so, and the entire system can power down for 4 minutes > and 58 seconds as far as it cares. If it's doing media streaming, it may > insist on having at least one CPU burst per screen refresh, and the CPU can > go to sleep for the rest of the 1/30th of a second. > >> How usually it is performed, i.e. is it some periodic process, which >> wakes up periodically to check criterion for cpu load ? If so, isn't >> it problematic in PM terms, becuase it mean that the system is resumed >> periodically (as a result of the the periodic timer's interrupt), and >> all devices are resumed ? > > No, it can be done on a per-device basis. > > 'powertop' is a possibly useful tool for playing with this stuff that will > let you look at power management on the fly. As far as I understand, suspend/respond PM is not per device, but for all system, and wakeup source will resume again the whole system. I think you mean runtime suspend/resume in the answer. _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
