On Tue, Nov 13, 2012 at 02:34:06AM +0100, Frederic Weisbecker wrote: > 2012/11/13 Josh Triplett <josh@xxxxxxxxxxxxxxxx>: > > On Tue, Nov 13, 2012 at 02:12:27AM +0100, Frederic Weisbecker wrote: > >> 2012/11/13 Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>: > >> > Hello! > >> > > >> > I know of people using TINY_RCU, TREE_RCU, and TREE_PREEMPT_RCU, but I > >> > have not heard of anyone using TINY_PREEMPT_RCU for whom TREE_PREEMPT_RCU > >> > was not a viable option (in contrast, the people running Linux on > >> > tiny-memmory systems typically use TINY_RCU). Of course, if no one > >> > really needs it, the proper thing to do is to remove it. > >> > > >> > So, if you need TINY_PREEMPT_RCU, please let me know. Otherwise, I will > >> > remove it, probably in the 3.9 timeframe. > >> > >> I don't use it personally but if you remove it, does that mean that > >> RCU couldn't be preemptible on UP? > > > > No, it would mean that on UP you could choose between TINY_RCU and > > TREE_PREEMPT_RCU, depending on whether you want tiny or preemptible. > > Ok. I thought the TREE version wasn't possible anymore on UP when I > saw some patches that removed optimizations for nr_online_cpus=1. > Hence the confusion. Those optimizations are not critically important. That said, yes, I will need to restart testing of TREE_PREEMPT_RCU on !SMP kernels. 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
