[2.6 patch] x86: revert X86_HT semantics change

[2.6 patch] x86: revert X86_HT semantics change

[Adrian Bunk]

The x86 unification resulted in CONFIG_X86_HT no longer being
set if (X86_32 && MK8).

After grep'ing through the tree I think the problem is that different 
places have different assumptions about the semantics of CONFIG_X86_HT,
either:
- hyperthreading or
- multicore
and the SCHED_SMT and SCHED_MC dependencies are just one of the 
symptoms.

This should be sorted out properly, but until then we should keep the 
2.6.23 status quo.

Signed-off-by: Adrian Bunk <bunk@kernel.org>

---

 arch/x86/Kconfig |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

18fef247715449d36438fe4de59fdf430f1b5c37 
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 1eb5997..2c357f0 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -148,7 +148,8 @@ config X86_SMP
 
 config X86_HT
 	bool
-	depends on SMP && !(X86_VISWS || X86_VOYAGER || MK8)
+	depends on SMP
+	depends on (X86_32 && !(X86_VISWS || X86_VOYAGER)) || (X86_64 && !MK8)
 	default y
 
 config X86_BIOS_REBOOT
@@ -476,7 +477,7 @@ config NR_CPUS
 
 config SCHED_SMT
 	bool "SMT (Hyperthreading) scheduler support"
-	depends on (X86_64 && SMP) || (X86_32 && X86_HT)
+	depends on X86_HT
 	help
 	  SMT scheduler support improves the CPU scheduler's decision making
 	  when dealing with Intel Pentium 4 chips with HyperThreading at a
@@ -485,7 +486,7 @@ config SCHED_SMT
 
 config SCHED_MC
 	bool "Multi-core scheduler support"
-	depends on (X86_64 && SMP) || (X86_32 && X86_HT)
+	depends on X86_HT
 	default y
 	help
 	  Multi-core scheduler support improves the CPU scheduler's decision

Re: [2.6 patch] x86: revert X86_HT semantics change

[Sam Ravnborg]

On Thu, Nov 15, 2007 at 05:17:03PM +0100, Adrian Bunk wrote:
> The x86 unification resulted in CONFIG_X86_HT no longer being
> set if (X86_32 && MK8).
Yup - my bad. I wrongly assumed MK8 was an X86_64 thing.

Thanks for fixing this.
> 
> After grep'ing through the tree I think the problem is that different 
> places have different assumptions about the semantics of CONFIG_X86_HT,
> either:
> - hyperthreading or
> - multicore
> and the SCHED_SMT and SCHED_MC dependencies are just one of the 
> symptoms.
> 
> This should be sorted out properly, but until then we should keep the 
> 2.6.23 status quo.
> 
> Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>

I assume Thomas & Co will forward the patch.

	Sam

Re: [2.6 patch] x86: revert X86_HT semantics change

[Thomas Gleixner]

On Thu, 15 Nov 2007, Sam Ravnborg wrote:

> On Thu, Nov 15, 2007 at 05:17:03PM +0100, Adrian Bunk wrote:
> > The x86 unification resulted in CONFIG_X86_HT no longer being
> > set if (X86_32 && MK8).
> Yup - my bad. I wrongly assumed MK8 was an X86_64 thing.
> 
> Thanks for fixing this.
> > 
> > After grep'ing through the tree I think the problem is that different 
> > places have different assumptions about the semantics of CONFIG_X86_HT,
> > either:
> > - hyperthreading or
> > - multicore
> > and the SCHED_SMT and SCHED_MC dependencies are just one of the 
> > symptoms.
> > 
> > This should be sorted out properly, but until then we should keep the 
> > 2.6.23 status quo.
> > 
> > Signed-off-by: Adrian Bunk <bunk@kernel.org>
> Acked-by: Sam Ravnborg <sam@ravnborg.org>
> 
> I assume Thomas & Co will forward the patch.

After looking what does what and fixing it. 

Right now this patch is not a 1:1 replacement of the .23 status quo,
as it now makes SCHED_SMT and SCHED_HT depend on !MK8 for 64bit.

     tglx

[2.6 patch] x86: revert X86_HT semantics change

[Adrian Bunk]

On Thu, Nov 15, 2007 at 07:07:11PM +0100, Thomas Gleixner wrote:
> On Thu, 15 Nov 2007, Sam Ravnborg wrote:
> 
> > On Thu, Nov 15, 2007 at 05:17:03PM +0100, Adrian Bunk wrote:
> > > The x86 unification resulted in CONFIG_X86_HT no longer being
> > > set if (X86_32 && MK8).
> > Yup - my bad. I wrongly assumed MK8 was an X86_64 thing.
> > 
> > Thanks for fixing this.
> > > 
> > > After grep'ing through the tree I think the problem is that different 
> > > places have different assumptions about the semantics of CONFIG_X86_HT,
> > > either:
> > > - hyperthreading or
> > > - multicore
> > > and the SCHED_SMT and SCHED_MC dependencies are just one of the 
> > > symptoms.
> > > 
> > > This should be sorted out properly, but until then we should keep the 
> > > 2.6.23 status quo.
> > > 
> > > Signed-off-by: Adrian Bunk <bunk@kernel.org>
> > Acked-by: Sam Ravnborg <sam@ravnborg.org>
> > 
> > I assume Thomas & Co will forward the patch.
> 
> After looking what does what and fixing it. 
> 
> Right now this patch is not a 1:1 replacement of the .23 status quo,
> as it now makes SCHED_SMT and SCHED_HT depend on !MK8 for 64bit.

*searches brown paperbag*

Thanks for spotting, fixed patch below.

>      tglx

cu
Adrian


<--  snip  -->


The x86 unification resulted in CONFIG_X86_HT no longer being
set if (X86_32 && MK8).

After grep'ing through the tree I think the problem is that different
places have different assumptions about the semantics of CONFIG_X86_HT,
either
- hyperthreading or
- multicore

This should be sorted out properly, but until then we should keep the
2.6.23 status quo.

Signed-off-by: Adrian Bunk <bunk@kernel.org>

---
480a5ae48036f6825a5a111db87da05e298327d6 
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index af1b1ca..5871b44 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -148,7 +148,8 @@ config X86_SMP
 
 config X86_HT
 	bool
-	depends on SMP && !(X86_VISWS || X86_VOYAGER || MK8)
+	depends on SMP
+	depends on (X86_32 && !(X86_VISWS || X86_VOYAGER)) || (X86_64 && !MK8)
 	default y
 
 config X86_BIOS_REBOOT

Re: [2.6 patch] x86: revert X86_HT semantics change

[Sam Ravnborg]

On Thu, Nov 15, 2007 at 07:07:11PM +0100, Thomas Gleixner wrote:
> On Thu, 15 Nov 2007, Sam Ravnborg wrote:
> 
> > On Thu, Nov 15, 2007 at 05:17:03PM +0100, Adrian Bunk wrote:
> > > The x86 unification resulted in CONFIG_X86_HT no longer being
> > > set if (X86_32 && MK8).
> > Yup - my bad. I wrongly assumed MK8 was an X86_64 thing.
> > 
> > Thanks for fixing this.
> > > 
> > > After grep'ing through the tree I think the problem is that different 
> > > places have different assumptions about the semantics of CONFIG_X86_HT,
> > > either:
> > > - hyperthreading or
> > > - multicore
> > > and the SCHED_SMT and SCHED_MC dependencies are just one of the 
> > > symptoms.
> > > 
> > > This should be sorted out properly, but until then we should keep the 
> > > 2.6.23 status quo.
> > > 
> > > Signed-off-by: Adrian Bunk <bunk@kernel.org>
> > Acked-by: Sam Ravnborg <sam@ravnborg.org>
> > 
> > I assume Thomas & Co will forward the patch.
> 
> After looking what does what and fixing it. 
> 
> Right now this patch is not a 1:1 replacement of the .23 status quo,
> as it now makes SCHED_SMT and SCHED_HT depend on !MK8 for 64bit.

I assumed this was intentional - Adrian?

	Sam

Re: [2.6 patch] x86: revert X86_HT semantics change

[Adrian Bunk]

On Thu, Nov 15, 2007 at 07:42:55PM +0100, Sam Ravnborg wrote:
> On Thu, Nov 15, 2007 at 07:07:11PM +0100, Thomas Gleixner wrote:
> > On Thu, 15 Nov 2007, Sam Ravnborg wrote:
> > 
> > > On Thu, Nov 15, 2007 at 05:17:03PM +0100, Adrian Bunk wrote:
> > > > The x86 unification resulted in CONFIG_X86_HT no longer being
> > > > set if (X86_32 && MK8).
> > > Yup - my bad. I wrongly assumed MK8 was an X86_64 thing.
> > > 
> > > Thanks for fixing this.
> > > > 
> > > > After grep'ing through the tree I think the problem is that different 
> > > > places have different assumptions about the semantics of CONFIG_X86_HT,
> > > > either:
> > > > - hyperthreading or
> > > > - multicore
> > > > and the SCHED_SMT and SCHED_MC dependencies are just one of the 
> > > > symptoms.
> > > > 
> > > > This should be sorted out properly, but until then we should keep the 
> > > > 2.6.23 status quo.
> > > > 
> > > > Signed-off-by: Adrian Bunk <bunk@kernel.org>
> > > Acked-by: Sam Ravnborg <sam@ravnborg.org>
> > > 
> > > I assume Thomas & Co will forward the patch.
> > 
> > After looking what does what and fixing it. 
> > 
> > Right now this patch is not a 1:1 replacement of the .23 status quo,
> > as it now makes SCHED_SMT and SCHED_HT depend on !MK8 for 64bit.
> 
> I assumed this was intentional - Adrian?

No, it was just buggy...

> 	Sam

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [2.6 patch] x86: revert X86_HT semantics change

[Ingo Molnar]

* Adrian Bunk <bunk@kernel.org> wrote:

> The x86 unification resulted in CONFIG_X86_HT no longer being set if 
> (X86_32 && MK8).
> 
> After grep'ing through the tree I think the problem is that different
> places have different assumptions about the semantics of CONFIG_X86_HT,
> either
> - hyperthreading or
> - multicore
> 
> This should be sorted out properly, but until then we should keep the
> 2.6.23 status quo.
> 
> Signed-off-by: Adrian Bunk <bunk@kernel.org>

thanks, applied. This is for 2.6.24, right?

	Ingo

Re: [2.6 patch] x86: revert X86_HT semantics change

[Adrian Bunk]

On Tue, Dec 04, 2007 at 02:29:05PM +0100, Ingo Molnar wrote:
> 
> * Adrian Bunk <bunk@kernel.org> wrote:
> 
> > The x86 unification resulted in CONFIG_X86_HT no longer being set if 
> > (X86_32 && MK8).
> > 
> > After grep'ing through the tree I think the problem is that different
> > places have different assumptions about the semantics of CONFIG_X86_HT,
> > either
> > - hyperthreading or
> > - multicore
> > 
> > This should be sorted out properly, but until then we should keep the
> > 2.6.23 status quo.
> > 
> > Signed-off-by: Adrian Bunk <bunk@kernel.org>
> 
> thanks, applied. This is for 2.6.24, right?

Yes.

> 	Ingo

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed