On Tue, 4 Mar 2008, Paul E. McKenney wrote: > > The original preemptible-RCU patch put the choice between classic and > preemptible RCU into kernel/Kconfig.preempt, which resulted in build > failures on machines not supporting CONFIG_PREEMPT. This choice was > therefore moved to init/Kconfig, which worked, but placed the choice > between classic and preemptible RCU at the top level, a very obtuse choice > indeed. This patch changes from the Kconfig "choice" mechanism to a pair > of booleans, only one of which (CONFIG_PREEMPT_RCU) is user-visible, > and is located in kernel/Kconfig.preempt, where one would expect it > to be. The other (CONFIG_CLASSIC_RCU) is in init/Kconfig so that it > is available to all architectures, hopefully avoiding build breakage. > Thanks to Roman Zippel for suggesting this approach. > > I have tested this, but sadly do not have access to a machine that does > not support CONFIG_PREEMPT. However, I did edit my config in an attempt > to simulate this situation. One minor comment, but otherwise: Acked-by: Steven Rostedt <srostedt@xxxxxxxxxx> > > Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> > config CLASSIC_RCU > - bool "Classic RCU" > + def_bool !PREEMPT_RCU > help > This option selects the classic RCU implementation that is > designed for best read-side performance on non-realtime > - systems. > - > - Say Y if you are unsure. > - You can get rid of the "help" part since it isn't visible to users. -- Steve -- 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
