On Tue, 2008-02-05 at 15:37 -0800, Max Krasnyanskiy wrote: > Folks, > > I just realized that in latest Linus' tree following sysctls are under > SCHED_DEBUG: > sched_rt_period > sched_rt_ratio > > I do not believe that is correct. I know that we do not want to expose > scheduler knobs > in general but theses are not the heuristic kind of knobs. There is no way > the scheduler > can magically figure out what the correct setting should be here.
Yeah, since fixed. > Also shouldn't those new RT features that recently went be configurable and > _disabled_ > by default ? For example "RT watchdog" and "RT throttling" actually seem very > questionable. > SCHED_FIFO is clearly defined as > " > A SCHED_FIFO process runs until either it is blocked by an I/O request, it > is preempted > by a higher priority process, or it calls sched_yield(2). > " The watchdog is disabled by default, the bandwidth is .95s every 1s, which is mainly a safe-guard against run-away real-time tasks. As long as real-time usage stays within those limits nothing happens. If you don't like it set sched_rt_runtime [*] to -1. [*] provided in the interface changes posted a few days ago. > Both the watchdog and the throttling are clearly braking that rule. I think > it's good to have > those features but not enabled by default and certainly not with sysctls that > disable them > hidden under debugging. > How about this: > - We introduce Kconfig options for them ? I don't see why this would be needed. > - Expose all rt sysctls outside of #ifdef DEBUG Already did this somewhere along the line. > btw I can see "watchdog" being very useful to catch hard-RT tasks that exceed > the deadline. > But's it gotta be per thread. It is. > Single setting per user is not enough. Unless a use has a single RT task. ? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
