On Thu, 2014-07-03 at 22:05 -0700, Paul E. McKenney wrote: > On Fri, Jul 04, 2014 at 05:23:56AM +0200, Mike Galbraith wrote:
> > Turn it on and don't worry about it is exactly what distros want the > > obscure feature with very few users to be. Last time I did a drive-by, > > my boxen said I should continue to worry about it ;-) > > Yep, which is the reason for the patch on the last email. > > Then again, exactly which feature and which reason for worry? NO_HZ_FULL. I tried ALL a while back, box instantly called me an idiot. Maybe that has improved since, dunno. Last drive-by I didn't do much overhead measurement, stuck mostly functionality, and it still had rough edges that enterprise users may not fully appreciate. Trying to let 60 of 64 cores do 100% compute showed some cores having a hard time entering tickless at all, and ~200us spikes that I think are due to tick losing skew.. told Frederic I'd take a peek at that, but haven't had time yet. There were other known things as well, like timers and workqueues for which there are patches floating around. All in all, it was waving the men at work sign, pointing at the "Say N" by the config option, and suggesting that ignoring that would not be the cleverest of moves. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
