Patchwork [RFC,powerpc] make CONFIG_NUMA depends on CONFIG_SMP

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Submitter Li Zhong
Date May 30, 2012, 9:31 a.m.
Message ID <1338370318.3637.12.camel@ThinkPad-T420>
Download mbox | patch
Permalink /patch/161911/
State Changes Requested
Delegated to: Michael Ellerman
Headers show

Comments

Li Zhong - May 30, 2012, 9:31 a.m.
I'm not sure whether it makes sense to add this dependency to avoid
CONFI_NUMA && !CONFIG_SMP. 

I want to do this because I saw some build errors on next-tree when
compiling with CONFIG_SMP disabled, and it seems they are caused by some
codes under the CONFIG_NUMA #ifdefs.  

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
---
 arch/powerpc/Kconfig |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
Michael Ellerman - April 18, 2013, 1:46 a.m.
On Wed, May 30, 2012 at 05:31:58PM +0800, Li Zhong wrote:
> I'm not sure whether it makes sense to add this dependency to avoid
> CONFI_NUMA && !CONFIG_SMP. 
> 
> I want to do this because I saw some build errors on next-tree when
> compiling with CONFIG_SMP disabled, and it seems they are caused by some
> codes under the CONFIG_NUMA #ifdefs.  

This seems to make sense to me. Can you please repost with a better
changelog and a description of the actual build error you were seeing.

cheers
Li Zhong - April 19, 2013, 2:10 a.m.
On Thu, 2013-04-18 at 11:46 +1000, Michael Ellerman wrote:
> On Wed, May 30, 2012 at 05:31:58PM +0800, Li Zhong wrote:
> > I'm not sure whether it makes sense to add this dependency to avoid
> > CONFI_NUMA && !CONFIG_SMP. 
> > 
> > I want to do this because I saw some build errors on next-tree when
> > compiling with CONFIG_SMP disabled, and it seems they are caused by some
> > codes under the CONFIG_NUMA #ifdefs.  
> 
> This seems to make sense to me. Can you please repost with a better
> changelog and a description of the actual build error you were seeing.

I tried it today, but didn't find any build errors any more, guess those
errors should have already been fixed. 

But it seems to me by disabling CONFIG_NUMA when CONFIG_SMP is disabled,
could at least prevent some unnecessary code being compiled into the
kernel. (After building a kernel with/without CONFIG_NUMA just now, it
seems that the vmlinux is ~100K smaller without CONFIG_NUMA).

I'm not sure whether this is still needed. 

Thanks, Zhong

> 
> cheers
>
Michael Ellerman - April 19, 2013, 7:20 a.m.
On Fri, 2013-04-19 at 10:10 +0800, Li Zhong wrote:
> On Thu, 2013-04-18 at 11:46 +1000, Michael Ellerman wrote:
> > On Wed, May 30, 2012 at 05:31:58PM +0800, Li Zhong wrote:
> > > I'm not sure whether it makes sense to add this dependency to avoid
> > > CONFI_NUMA && !CONFIG_SMP. 
> > > 
> > > I want to do this because I saw some build errors on next-tree when
> > > compiling with CONFIG_SMP disabled, and it seems they are caused by some
> > > codes under the CONFIG_NUMA #ifdefs.  
> > 
> > This seems to make sense to me. Can you please repost with a better
> > changelog and a description of the actual build error you were seeing.
> 
> I tried it today, but didn't find any build errors any more, guess those
> errors should have already been fixed. 
> 
> But it seems to me by disabling CONFIG_NUMA when CONFIG_SMP is disabled,
> could at least prevent some unnecessary code being compiled into the
> kernel. (After building a kernel with/without CONFIG_NUMA just now, it
> seems that the vmlinux is ~100K smaller without CONFIG_NUMA).
> 
> I'm not sure whether this is still needed. 

Yeah we'll leave your patch out. Unless someone cares deeply about the
size of the UP build, I think it's better to just leave them as separate
options.

cheers

Patch

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 050cb37..b2aa74b 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -394,7 +394,7 @@  config IRQ_ALL_CPUS
 
 config NUMA
 	bool "NUMA support"
-	depends on PPC64
+	depends on PPC64 && SMP
 	default y if SMP && PPC_PSERIES
 
 config NODES_SHIFT