* Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > On Fri, 4 Jun 2010, Ingo Molnar wrote: > > > > This allows a task to 'exclude' other tasks that dont have low-latency > > requirements. Crappy apps would have a large latency value, so they'd > > be idled out when a privileged task sets the exclusion level low enough. > > Quite frankly, this sounds fundamentally broken. > > Think deadlock. The high-latency task got a lock, and now you're excluding > it because it scheduled away. Mail was a bit too long already so i trimmed it at the wrong place :-/ What you say is absolutely true, hence this would be driven via sched_tick() + TIF notifiers - i.e. only ever treat user-mode tasks as 'idle-able'. This can be done with no overhead to the regular fastpaths. The TIF notifier would be the one scheduling to idle - and would thus do it only to user-mode tasks. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
