linux/arch
Frederic Weisbecker 3451d0243c nohz: Rename CONFIG_NO_HZ to CONFIG_NO_HZ_COMMON
We are planning to convert the dynticks Kconfig options layout
into a choice menu. The user must be able to easily pick
any of the following implementations: constant periodic tick,
idle dynticks, full dynticks.

As this implies a mutual exclusion, the two dynticks implementions
need to converge on the selection of a common Kconfig option in order
to ease the sharing of a common infrastructure.

It would thus seem pretty natural to reuse CONFIG_NO_HZ to
that end. It already implements all the idle dynticks code
and the full dynticks depends on all that code for now.
So ideally the choice menu would propose CONFIG_NO_HZ_IDLE and
CONFIG_NO_HZ_EXTENDED then both would select CONFIG_NO_HZ.

On the other hand we want to stay backward compatible: if
CONFIG_NO_HZ is set in an older config file, we want to
enable CONFIG_NO_HZ_IDLE by default.

But we can't afford both at the same time or we run into
a circular dependency:

1) CONFIG_NO_HZ_IDLE and CONFIG_NO_HZ_EXTENDED both select
   CONFIG_NO_HZ
2) If CONFIG_NO_HZ is set, we default to CONFIG_NO_HZ_IDLE

We might be able to support that from Kconfig/Kbuild but it
may not be wise to introduce such a confusing behaviour.

So to solve this, create a new CONFIG_NO_HZ_COMMON option
which gathers the common code between idle and full dynticks
(that common code for now is simply the idle dynticks code)
and select it from their referring Kconfig.

Then we'll later create CONFIG_NO_HZ_IDLE and map CONFIG_NO_HZ
to it for backward compatibility.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-04-03 13:56:03 +02:00
..
alpha arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
arc ARC: split elf.h into uapi and export it for userspace 2013-02-27 20:00:26 +05:30
arm Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm 2013-03-03 11:54:39 -08:00
arm64 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-03-02 08:34:06 -08:00
avr32 arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
blackfin Merge branch 'timer/cleanup' into late/mvebu2 2013-02-28 18:54:15 +01:00
c6x Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
cris Merge branch 'timer/cleanup' into late/mvebu2 2013-02-28 18:54:15 +01:00
frv arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
h8300 arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
hexagon Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
ia64 hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
m32r Merge branch 'timer/cleanup' into late/mvebu2 2013-02-28 18:54:15 +01:00
m68k Merge branch 'timer/cleanup' into late/mvebu2 2013-02-28 18:54:15 +01:00
metag ImgTec Meta architecture changes for v3.9-rc1 2013-03-03 12:06:09 -08:00
microblaze arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
mips Merge git://www.linux-watchdog.org/linux-watchdog 2013-03-03 10:23:29 -08:00
mn10300 arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
openrisc arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
parisc Merge branch 'fixes-for-3.9-latest' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2013-03-03 12:57:38 -08:00
powerpc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-03-02 08:34:06 -08:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-03-03 13:23:03 -08:00
score arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
sh hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
sparc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-03-02 08:34:06 -08:00
tile arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
um nohz: Rename CONFIG_NO_HZ to CONFIG_NO_HZ_COMMON 2013-04-03 13:56:03 +02:00
unicore32 arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
x86 context_tracking: Restore correct previous context state on exception exit 2013-03-07 17:10:11 +01:00
xtensa arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS 2013-02-27 19:10:23 -08:00
.gitignore
Kconfig ImgTec Meta architecture changes for v3.9-rc1 2013-03-03 12:06:09 -08:00