Re: [RFC][PATCH 6/6] sched: consolidate config options

[Peter Zijlstra <peterz@infradead.org>]

On Wed, Sep 17, 2014 at 03:33:20PM -0700, Dave Hansen wrote:
> diff -puN /dev/null kernel/sched/Kconfig
> --- /dev/null	2014-04-10 11:28:14.066815724 -0700
> +++ b/kernel/sched/Kconfig	2014-09-17 15:28:58.620622789 -0700
> @@ -0,0 +1,42 @@
> +config ARCH_ENABLE_SCHED_MC
> +	depends on SMP
> +	def_bool n
> +
> +config ARCH_ENABLE_SCHED_BOOK
> +	depends on SMP
> +	def_bool n
> +
> +config ARCH_ENABLE_SCHED_SMT
> +	depends on SMP
> +	def_bool n
> +
> +config SCHED_MC
> +	bool "Multi-core scheduler support"
> +	default n if s390
> +	default y
> +	depends on ARCH_ENABLE_SCHED_MC
> +	help
> +	  Multi-core scheduler support improves the CPU scheduler's decision
> +	  making when dealing with multi-core CPU chips at a cost of slightly
> +	  increased overhead in some places. If unsure say N here.
> +
> +config SCHED_BOOK
> +	def_bool y
> +	prompt "Book scheduler support"
> +	depends on ARCH_ENABLE_SCHED_BOOK
> +	select SCHED_MC
> +	help
> +	  Book scheduler support improves the CPU scheduler's decision making
> +	  when dealing with machines that have several books.
> +
> +	  Currenltly only used on s390 which has only a single NUMA node.
> +	  Books are collections of CPUs that are grouped similarly to a NUMA
> +	  node, but without the same memory properites that NUMA nodes have.

Nothing outside of s390 knows about SCHED_BOOK, it doesn't make sense to
have that here.

> +config SCHED_SMT
> +	bool "SMT scheduler support"
> +	depends on ARCH_ENABLE_SCHED_SMT
> +	help
> +	  Improves the CPU scheduler's decision making when dealing with
> +	  MultiThreading at a cost of slightly increased overhead in some
> +	  places. If unsure say N here.
> _