On Mon, Nov 07, 2016 at 09:35:46AM -0800, Josh Triplett wrote: > On Mon, Nov 07, 2016 at 06:30:30PM +0100, Sebastian Andrzej Siewior wrote: > > On 2016-11-07 12:19:39 [-0500], Steven Rostedt wrote: > > > I agree, but if this creates a boot time regression in large machines, > > > it may not be warranted. > > > > > > I know Linus usually doesn't like options with default y, but this may > > > be one of those exceptions. Perhaps we should make it on by default and > > > say in the config "if you have a machine with 100s or 1000s of CPUs, > > > you may want to disable this". > > > > The default could change if we know where the limit is. I have access to > > a box with approx 140 CPUs so I could check there if it is already bad. > > But everything above that / in the 1000 range is a different story. > > Right; if we can characterize what machines it benefits and what > machines it hurts, we can automatically detect and run the appropriate > case with no configuration option needed. I very much like this approach! Anyone have access to large systems on which this experiment could be carried out? In the absence of new data, I would just set the cutoff at 256 CPUs, as I have done in the past. Thanx, Paul -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
