[PATCH] kernel: prevent unnecessary rebuilding due to config_data.gz

[PATCH] kernel: prevent unnecessary rebuilding due to config_data.gz

[Peter Foley]

When IKCONFIG is built-in make oldconfig will cause the kernel to be 
relinked even if .config didn't change. This happens because of a 
config_data.gz dependency on .config. This patch changes the if_changed to 
a filechk so that config_data.h is only rebuilt when the contents 
have actually changed.

Signed-off-by: Peter Foley <pefoley2@verizon.net>
---
 kernel/Makefile |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/Makefile b/kernel/Makefile
index 2d64cfc..d06467f 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -125,11 +125,10 @@ targets += config_data.gz
 $(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE
 	$(call if_changed,gzip)
 
-quiet_cmd_ikconfiggz = IKCFG   $@
-      cmd_ikconfiggz = (echo "static const char kernel_config_data[] __used = MAGIC_START"; cat $< | scripts/bin2c; echo "MAGIC_END;") > $@
+      filechk_ikconfiggz = (echo "static const char kernel_config_data[] __used = MAGIC_START"; cat $< | scripts/bin2c; echo "MAGIC_END;")
 targets += config_data.h
 $(obj)/config_data.h: $(obj)/config_data.gz FORCE
-	$(call if_changed,ikconfiggz)
+	$(call filechk,ikconfiggz)
 
 $(obj)/time.o: $(obj)/timeconst.h
 
-- 
1.7.5.3

Re: [PATCH] kernel: prevent unnecessary rebuilding due to config_data.gz

[Randy Dunlap]

On Tue, 05 Jul 2011 19:42:18 -0400 (EDT) Peter Foley wrote:

> When IKCONFIG is built-in make oldconfig will cause the kernel to be 
> relinked even if .config didn't change. This happens because of a 
> config_data.gz dependency on .config. This patch changes the if_changed to 
> a filechk so that config_data.h is only rebuilt when the contents 
> have actually changed.
> 
> Signed-off-by: Peter Foley <pefoley2@verizon.net>

Michal,
If this looks OK to you, please merge it.

Thanks.

> ---
>  kernel/Makefile |    5 ++---
>  1 files changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/Makefile b/kernel/Makefile
> index 2d64cfc..d06467f 100644
> --- a/kernel/Makefile
> +++ b/kernel/Makefile
> @@ -125,11 +125,10 @@ targets += config_data.gz
>  $(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE
>  	$(call if_changed,gzip)
>  
> -quiet_cmd_ikconfiggz = IKCFG   $@
> -      cmd_ikconfiggz = (echo "static const char kernel_config_data[] __used = MAGIC_START"; cat $< | scripts/bin2c; echo "MAGIC_END;") > $@
> +      filechk_ikconfiggz = (echo "static const char kernel_config_data[] __used = MAGIC_START"; cat $< | scripts/bin2c; echo "MAGIC_END;")
>  targets += config_data.h
>  $(obj)/config_data.h: $(obj)/config_data.gz FORCE
> -	$(call if_changed,ikconfiggz)
> +	$(call filechk,ikconfiggz)
>  
>  $(obj)/time.o: $(obj)/timeconst.h
>  
> -- 


---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: [PATCH] kernel: prevent unnecessary rebuilding due to config_data.gz

[Peter Foley]

On Wed, 6 Jul 2011, Randy Dunlap wrote:

> On Tue, 05 Jul 2011 19:42:18 -0400 (EDT) Peter Foley wrote:
> 
> > When IKCONFIG is built-in make oldconfig will cause the kernel to be 
> > relinked even if .config didn't change. This happens because of a 
> > config_data.gz dependency on .config. This patch changes the if_changed to 
> > a filechk so that config_data.h is only rebuilt when the contents 
> > have actually changed.
> > 
> > Signed-off-by: Peter Foley <pefoley2@verizon.net>
> 
> Michal,
> If this looks OK to you, please merge it.
> 
> Thanks.
> 
> > ---
> >  kernel/Makefile |    5 ++---
> >  1 files changed, 2 insertions(+), 3 deletions(-)
> > 
> > diff --git a/kernel/Makefile b/kernel/Makefile
> > index 2d64cfc..d06467f 100644
> > --- a/kernel/Makefile
> > +++ b/kernel/Makefile
> > @@ -125,11 +125,10 @@ targets += config_data.gz
> >  $(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE
> >  	$(call if_changed,gzip)
> >  
> > -quiet_cmd_ikconfiggz = IKCFG   $@
> > -      cmd_ikconfiggz = (echo "static const char kernel_config_data[] __used = MAGIC_START"; cat $< | scripts/bin2c; echo "MAGIC_END;") > $@
> > +      filechk_ikconfiggz = (echo "static const char kernel_config_data[] __used = MAGIC_START"; cat $< | scripts/bin2c; echo "MAGIC_END;")
> >  targets += config_data.h
> >  $(obj)/config_data.h: $(obj)/config_data.gz FORCE
> > -	$(call if_changed,ikconfiggz)
> > +	$(call filechk,ikconfiggz)
> >  
> >  $(obj)/time.o: $(obj)/timeconst.h
> >  
> > -- 
> 
> 
> ---
> ~Randy
> *** Remember to use Documentation/SubmitChecklist when testing your code ***
> 

Ping?

Re: [PATCH] kernel: prevent unnecessary rebuilding due to config_data.gz

[Michal Marek]

On Wed, Jul 06, 2011 at 08:33:29AM -0700, Randy Dunlap wrote:
> On Tue, 05 Jul 2011 19:42:18 -0400 (EDT) Peter Foley wrote:
> 
> > When IKCONFIG is built-in make oldconfig will cause the kernel to be 
> > relinked even if .config didn't change. This happens because of a 
> > config_data.gz dependency on .config. This patch changes the if_changed to 
> > a filechk so that config_data.h is only rebuilt when the contents 
> > have actually changed.
> > 
> > Signed-off-by: Peter Foley <pefoley2@verizon.net>
> 
> Michal,
> If this looks OK to you, please merge it.

Thanks, merged to kbuild-2.6.git#kbuild.

Michal