On Fri, 2010-10-08 at 11:25 +0200, ext Christoph Hellwig wrote: > On Fri, Oct 08, 2010 at 04:35:14PM +0800, Yong Wang wrote: > > sync_supers task currently wakes up periodically for superblock > > writeback. This hurts power on battery driven devices. This patch > > turns this housekeeping timer into a deferable timer so that it > > does not fire when system is really idle. > > How long can the timer be defereed? We can't simply stop writing > out data for a long time. I think the current timer value should be > the upper bound, but allowing to fire earlier to run during the > same wakeup cycle as others is fine. Infinitely. There are range hrtimers which can do exactly what you said - you specify the hard and soft limits there. -- Best Regards, Artem Bityutskiy (ÐÑÑÑÐ ÐÐÑÑÑÐÐÐ) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>