On Wed, Jul 01, 2015 at 12:09:39PM +0200, Peter Zijlstra wrote: > On Tue, Jun 30, 2015 at 04:46:33PM -0700, j...@joshtriplett.org wrote: > > Consider it a fairly weak concern against. Increasing performance seems > > like a good thing in general; I just don't relish the future "feels less > > responsive" bug reports that take a long time to track down and turn out > > to be "this completely unrelated driver was loaded and started using > > expedited grace periods". > > random drivers, or for that matter, new-code of any sort. Should _NOT_ > be using expedited grace periods. > > They're a horrid hack only suitable for unfixable ABI.
Let me repeat, just in case I've not been clear. Expedited grace periods are _BAD_ and should be avoided at all costs. They perturb the _entire_ machine. Yes we can polish the turd, but in the end its still a turd. Sadly people seem to have taken a liking to them, ooh a make RCU go faster button. And there's not been much if any pushback on people using it. -- 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/
