NO_HZ Kconfig rework

NO_HZ Kconfig rework

[Daniel Walker]

I got NO_HZ working on ARM, but because the ARM tree already
extensively implements NO_IDLE_HZ I had to make NO_HZ a
completely seprate option.

Signed-Off-By: Daniel Walker <dwalker@mvista.com>

---
 kernel/sysctl.c     |    2 +-
 kernel/time/Kconfig |    5 -----
 kernel/timer.c      |    2 +-
 3 files changed, 2 insertions(+), 7 deletions(-)

Index: linux-2.6.17/kernel/sysctl.c
===================================================================
--- linux-2.6.17.orig/kernel/sysctl.c
+++ linux-2.6.17/kernel/sysctl.c
@@ -581,7 +581,7 @@ static ctl_table kern_table[] = {
 		.proc_handler	= &proc_dointvec,
 	},
 #endif
-#ifdef CONFIG_NO_IDLE_HZ
+#ifdef CONFIG_NO_HZ
 	{
 		.ctl_name       = KERN_TIMEOUT_GRANULARITY,
 		.procname       = "timeout_granularity",
Index: linux-2.6.17/kernel/time/Kconfig
===================================================================
--- linux-2.6.17.orig/kernel/time/Kconfig
+++ linux-2.6.17/kernel/time/Kconfig
@@ -17,11 +17,6 @@ config NO_HZ
 	  only trigger on an as-needed basis both when the system is
 	  busy and when the system is idle.
 
-config NO_IDLE_HZ
-	bool
-	default y
-	depends on NO_HZ
-
 config HIGH_RES_RESOLUTION
 	int "High Resolution Timer resolution (nanoseconds)"
 	depends on HIGH_RES_TIMERS
Index: linux-2.6.17/kernel/timer.c
===================================================================
--- linux-2.6.17.orig/kernel/timer.c
+++ linux-2.6.17/kernel/timer.c
@@ -484,7 +484,7 @@ static inline void __run_timers(tvec_bas
 	set_running_timer(base, NULL);
 }
 
-#ifdef CONFIG_NO_IDLE_HZ
+#if defined(CONFIG_NO_IDLE_HZ) || defined(CONFIG_NO_HZ)
 /*
  * Find out when the next timer event is due to happen. This
  * is used on S/390 to stop all activity when a cpus is idle.

Re: NO_HZ Kconfig rework

[Pavel Machek]

On Mon 2006-06-26 09:16:37, Daniel Walker wrote:
> I got NO_HZ working on ARM, but because the ARM tree already
> extensively implements NO_IDLE_HZ I had to make NO_HZ a
> completely seprate option.

So... what is the difference between NO_HZ and NO_IDLE_HZ?
							Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: NO_HZ Kconfig rework

[Daniel Walker]

On Thu, 2006-06-29 at 11:42 +0200, Pavel Machek wrote:
> On Mon 2006-06-26 09:16:37, Daniel Walker wrote:
> > I got NO_HZ working on ARM, but because the ARM tree already
> > extensively implements NO_IDLE_HZ I had to make NO_HZ a
> > completely seprate option.
> 
> So... what is the difference between NO_HZ and NO_IDLE_HZ?

NO_HZ is a generic version of dynamic tick. NO_IDLE_HZ has some generic
parts but is mostly implemented by the architecture. In this case ARM
fully implements NO_IDLE_HZ, which then collides with NO_HZ if they
depend on each other.

Daniel

Re: NO_HZ Kconfig rework

[Thomas Gleixner]

Pavel,

On Thu, 2006-06-29 at 11:42 +0200, Pavel Machek wrote:
> On Mon 2006-06-26 09:16:37, Daniel Walker wrote:
> > I got NO_HZ working on ARM, but because the ARM tree already
> > extensively implements NO_IDLE_HZ I had to make NO_HZ a
> > completely seprate option.
> 
> So... what is the difference between NO_HZ and NO_IDLE_HZ?
> 							Pavel

Mostly a development vehicle. This will be removed once we are ready to
merge the existing arch implementations.

	tglx