On Mon, 2010-08-02 at 21:18 -0700, Arve Hjønnevåg wrote: > > o A power-aware application must be able to efficiently communicate > > its needs to the system, so that such communication can be > > performed on hot code paths. Communication via open() and > > close() is considered too slow, but communication via ioctl() > > is acceptable. > > > > The problem with using open and close to prevent an allow suspend is > not that it is too slow but that it interferes with collecting stats. Please elaborate on this. I expect the pm-qos stats interface will collect stats across user open/close because that's how it currently works. What's the problem? > The wakelock code has a sysfs interface that allow you to use a > open/write/close sequence to block or unblock suspend. There is no > limit to the amount of kernel memory that a process can consume with > this interface, so the suspend blocker patchset uses a /dev interface > with ioctls to block or unblock suspend and it destroys the kernel > object when the file descriptor is closed. This is an implementation detail only. The pm-qos objects are long lived, so their stats would be too. I would guess that explicit stat clearing might be a useful option. James _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
