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SubjectRe: RCU Kconfig help text
On Sat 2009-09-05 13:01:46, Paul E. McKenney wrote:
> On Sat, Sep 05, 2009 at 09:27:10AM -0400, Valdis.Kletnieks@vt.edu wrote:
> > init/Kconfig says:
> >
> > "choice
> > prompt "RCU Implementation"
> > default TREE_RCU
> >
> > config TREE_RCU
> > bool "Tree-based hierarchical RCU"
> > help
> > This option selects the RCU implementation that is
> > designed for very large SMP system with hundreds or
> > thousands of CPUs. It also scales down nicely to
> > smaller systems.
> >
> > config TREE_PREEMPT_RCU
> > bool "Preemptable tree-based hierarchical RCU"
> > depends on PREEMPT
> > help
> > This option selects the RCU implementation that is
> > designed for very large SMP systems with hundreds or
> > thousands of CPUs, but for which real-time response
> > is also required.
> >
> > endchoice"
> >
> > This leaves somebody who has a laptop wondering which choice is best for
> > a system with only one or two cores that has CONFIG_PREEMPT defined. One
> > choice says it scales down nicely, the other explicitly has a 'depends on
> > PREEMPT' attached to it...
> >
> > (Yes, I realize in practice, the RCU sections on a laptop are probably usually
> > so short they don't matter in practice. I finally concluded TREE_PREEMPT was
> > apparently a rename of CONFIG_PREEMPT_RCU and went with that since that was
> > working for me before...)
>
> Good point -- I will add the "It also scales down nicely to smaller
> systems" to TREE_PREEMPT_RCU.
>
> For -really- small systems, TINY_RCU will hopefully be there at some
> point, but it can only handle single-CPU systems.

If so, call it 'UP_RCU' or 'UNIPROCESSOR_RCU'?
Pavel

--
(english) http://www.livejournal.com/~pavelmachek
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