On Sun, Aug 09, 2009 at 11:30:10AM -0700, Paul E. McKenney wrote: > On Sun, Aug 09, 2009 at 01:10:08PM +0200, Ingo Molnar wrote: > > > > * Ingo Molnar <mingo@xxxxxxx> wrote: > > > > > > rcu: Add second diagnostic check for a possible CPU-hotplug race > > > > > > has a build problem too: > > > > > > kernel/built-in.o: In function `rcu_cpu_notified': > > > (.text+0x1d787): undefined reference to `cpu_notified' > > > kernel/built-in.o: In function `rcu_init': > > > (.init.text+0x1174): undefined reference to `cpu_notified' > > > kernel/built-in.o: In function `rcu_init': > > > (.init.text+0x11a8): undefined reference to `cpu_notified' > > > > > > Maybe we should simplify all those Kconfig rules? It's a maze. > > Or I could fix up my scripts so that I once again test the relevant > combinations -before- I submit the patch. :-/ That said, I could imagine the following simplifications: o CONFIG_SMP always implies CONFIG_HOTPLUG_CPU, eliminating the need to test CONFIG_SMP&&!CONFIG_HOTPLUG_CPU. o Make CONFIG_NO_HZ unconditional. (Now, -that- should get a reaction! For one thing, I am not sure that all architectures support CONFIG_NO_HZ.) o Eliminate the combination CONFIG_PREEMPT && CONFIG_TREE_RCU. In other words, make a preemptable kernel imply preemptable RCU and vice versa. o After sufficient testing, eliminate CONFIG_PREEMPT_RCU in favor of CONFIG_TREE_PREEMPT_RCU (currently under development). o After sufficient testing, make !CONFIG_SMP imply CONFIG_TINY_RCU. This might require a preemptable variant of CONFIG_TINY_RCU. There are probably quite a few similar simplifications. Thanx, Paul -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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