On Fri 18-05-12 00:04:33, Peter Zijlstra wrote: > On Tue, 2012-05-15 at 17:43 +0200, Jan Kara wrote: > > +static struct timer_list writeout_period_timer = > > + TIMER_DEFERRED_INITIALIZER(writeout_period, 0, 0); > > So the problem with using a deferred timer is that it 'ignores' idle > time. So if a very busy period is followed by a real quiet period you'd > expect all the proportions to have aged to 0, but they won't have. Ah, I see. Thanks for warning me. > One way to solve that is to track a jiffies count of the last time the > timer triggered and compute the missed periods from that and extend > fprop_new_period() to deal with period increments of more than 1. Yeah, that should be easy enough so I'll try it that way since I presume it's nicer to power usage to use deferred timers if it's reasonably possible. Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>