lkml.org 
[lkml]   [2013]   [Apr]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: rcu: Provide compile-time control for no-CBs CPUs
On Tue, Apr 30, 2013 at 03:21:26PM +0000, Linux Kernel wrote:

> +choice
> + prompt "Build-forced no-CBs CPUs"
> + default RCU_NOCB_CPU_NONE
> + help
> + This option allows no-CBs CPUs to be specified at build time.
> + Additional no-CBs CPUs may be specified by the rcu_nocbs=
> + boot parameter.
> +
> +config RCU_NOCB_CPU_NONE
> + bool "No build_forced no-CBs CPUs"
> + depends on RCU_NOCB_CPU
> + help
> + This option does not force any of the CPUs to be no-CBs CPUs.
> + Only CPUs designated by the rcu_nocbs= boot parameter will be
> + no-CBs CPUs.
> +
> +config RCU_NOCB_CPU_ZERO
> + bool "CPU 0 is a build_forced no-CBs CPU"
> + depends on RCU_NOCB_CPU
> + help
> + This option forces CPU 0 to be a no-CBs CPU. Additional CPUs
> + may be designated as no-CBs CPUs using the rcu_nocbs= boot
> + parameter will be no-CBs CPUs.
> +
> + Select this if CPU 0 needs to be a no-CBs CPU for real-time
> + or energy-efficiency reasons.
> +
> +config RCU_NOCB_CPU_ALL
> + bool "All CPUs are build_forced no-CBs CPUs"
> + depends on RCU_NOCB_CPU
> + help
> + This option forces all CPUs to be no-CBs CPUs. The rcu_nocbs=
> + boot parameter will be ignored.
> +
> + Select this if all CPUs need to be no-CBs CPUs for real-time
> + or energy-efficiency reasons.

Note that entering '?' when prompted in oldconfig only outputs the help
parameter from the choice section.

Additionally, nowhere in any of this text does it say what a "no-CB CPU" is,
or why I would care, or even what the downsides are for each option.

I nominate this changeset for an award for most obtuse kconfig text in 3.10 (so far)

Dave



\
 
 \ /
  Last update: 2013-04-30 21:21    [W:0.075 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site