Patchwork [U-Boot,1/2] common: Add CCACHE variable to allow use of ccache

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Submitter Marek Vasut
Date May 20, 2013, 5:25 p.m.
Message ID <1369070715-9585-2-git-send-email-marex@denx.de>
Download mbox | patch
Permalink /patch/245079/
State Deferred
Delegated to: Tom Rini
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Comments

Marek Vasut - May 20, 2013, 5:25 p.m.
Prefix HOSTCC and CC with CCACHE variable to allow easy use of ccache.
In case the user wants to use ccache, exporting CCACHE=ccache will do
the trick. It is of course possible to either make the cross-compiler
name into a shellscript which invokes the ccache and the compiler, but
setting this variable makes use of ccache easier and more convenient.

Using ccache becomes convenient when using MAKEALL for large build
tests, where the speedup after building the cache for the first time
is about 4-6 times.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Tom Rini <trini@ti.com>
---
 config.mk |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)
Wolfgang Denk - May 21, 2013, 12:39 p.m.
Dear Marek Vasut,

In message <1369070715-9585-2-git-send-email-marex@denx.de> you wrote:
> Prefix HOSTCC and CC with CCACHE variable to allow easy use of ccache.
> In case the user wants to use ccache, exporting CCACHE=ccache will do
> the trick. It is of course possible to either make the cross-compiler
> name into a shellscript which invokes the ccache and the compiler, but
> setting this variable makes use of ccache easier and more convenient.
...
> -AS	= $(CROSS_COMPILE)as
> +AS	= $(CCACHE) $(CROSS_COMPILE)as
>  
>  # Always use GNU ld
>  LD	= $(shell if $(CROSS_COMPILE)ld.bfd -v > /dev/null 2>&1; \
>  		then echo "$(CROSS_COMPILE)ld.bfd"; else echo "$(CROSS_COMPILE)ld"; fi;)
>  
> -CC	= $(CROSS_COMPILE)gcc
> +CC	= $(CCACHE) $(CROSS_COMPILE)gcc
>  CPP	= $(CC) -E

Why not for CPP ?

Best regards,

Wolfgang Denk
Marek Vasut - May 21, 2013, 3:04 p.m.
Dear Wolfgang Denk,

> Dear Marek Vasut,
> 
> In message <1369070715-9585-2-git-send-email-marex@denx.de> you wrote:
> > Prefix HOSTCC and CC with CCACHE variable to allow easy use of ccache.
> > In case the user wants to use ccache, exporting CCACHE=ccache will do
> > the trick. It is of course possible to either make the cross-compiler
> > name into a shellscript which invokes the ccache and the compiler, but
> > setting this variable makes use of ccache easier and more convenient.
> 
> ...
> 
> > -AS	= $(CROSS_COMPILE)as
> > +AS	= $(CCACHE) $(CROSS_COMPILE)as
> > 
> >  # Always use GNU ld
> >  LD	= $(shell if $(CROSS_COMPILE)ld.bfd -v > /dev/null 2>&1; \
> >  
> >  		then echo "$(CROSS_COMPILE)ld.bfd"; else echo 
"$(CROSS_COMPILE)ld";
> >  		fi;)
> > 
> > -CC	= $(CROSS_COMPILE)gcc
> > +CC	= $(CCACHE) $(CROSS_COMPILE)gcc
> > 
> >  CPP	= $(CC) -E
> 
> Why not for CPP ?

CPP is invoked via $(CC) -E and CCACHE is set for CC right above, so that'd call 
ccache twice.

Best regards,
Marek Vasut
York Sun - Aug. 21, 2013, 11:39 p.m.
On 05/20/2013 10:25 AM, Marek Vasut wrote:
> Prefix HOSTCC and CC with CCACHE variable to allow easy use of ccache.
> In case the user wants to use ccache, exporting CCACHE=ccache will do
> the trick. It is of course possible to either make the cross-compiler
> name into a shellscript which invokes the ccache and the compiler, but
> setting this variable makes use of ccache easier and more convenient.
> 
> Using ccache becomes convenient when using MAKEALL for large build
> tests, where the speedup after building the cache for the first time
> is about 4-6 times.
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> Cc: Tom Rini <trini@ti.com>
> 
> ---
> config.mk |    8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/config.mk b/config.mk
> index 1fd109f..d59ded2 100644
> --- a/config.mk
> +++ b/config.mk
> @@ -98,6 +98,8 @@ else
>  HOSTCC		= gcc
>  endif
>  
> +HOSTCC		:= $(CCACHE) $(HOSTCC)
> +
>  ifeq ($(HOSTOS),cygwin)
>  HOSTCFLAGS	+= -ansi
>  endif
> @@ -140,13 +142,13 @@ binutils-version = $(shell $(SHELL) $(SRCTREE)/tools/binutils-version.sh $(AS))
>  #
>  # Include the make variables (CC, etc...)
>  #
> -AS	= $(CROSS_COMPILE)as
> +AS	= $(CCACHE) $(CROSS_COMPILE)as
>  
>  # Always use GNU ld
>  LD	= $(shell if $(CROSS_COMPILE)ld.bfd -v > /dev/null 2>&1; \
>  		then echo "$(CROSS_COMPILE)ld.bfd"; else echo "$(CROSS_COMPILE)ld"; fi;)
>  
> -CC	= $(CROSS_COMPILE)gcc
> +CC	= $(CCACHE) $(CROSS_COMPILE)gcc
>  CPP	= $(CC) -E
>  AR	= $(CROSS_COMPILE)ar
>  NM	= $(CROSS_COMPILE)nm
> @@ -320,7 +322,7 @@ endif
>  
>  #########################################################################
>  
> -export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE \
> +export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE CCACHE \
>  	AS LD CC CPP AR NM STRIP OBJCOPY OBJDUMP MAKE
>  export	CONFIG_SYS_TEXT_BASE PLATFORM_CPPFLAGS PLATFORM_RELFLAGS CPPFLAGS CFLAGS AFLAGS
>  
> 

Where did this patch go? I found it useful.

York
Marek Vasut - Aug. 22, 2013, 2:51 a.m.
Dear York Sun,

> On 05/20/2013 10:25 AM, Marek Vasut wrote:
> > Prefix HOSTCC and CC with CCACHE variable to allow easy use of ccache.
> > In case the user wants to use ccache, exporting CCACHE=ccache will do
> > the trick. It is of course possible to either make the cross-compiler
> > name into a shellscript which invokes the ccache and the compiler, but
> > setting this variable makes use of ccache easier and more convenient.
> > 
> > Using ccache becomes convenient when using MAKEALL for large build
> > tests, where the speedup after building the cache for the first time
> > is about 4-6 times.
> > 
> > Signed-off-by: Marek Vasut <marex@denx.de>
> > Cc: Tom Rini <trini@ti.com>
> > 
> > ---
> > config.mk |    8 +++++---
> > 
> >  1 file changed, 5 insertions(+), 3 deletions(-)
> > 
> > diff --git a/config.mk b/config.mk
> > index 1fd109f..d59ded2 100644
> > --- a/config.mk
> > +++ b/config.mk
> > @@ -98,6 +98,8 @@ else
> > 
> >  HOSTCC		= gcc
> >  endif
> > 
> > +HOSTCC		:= $(CCACHE) $(HOSTCC)
> > +
> > 
> >  ifeq ($(HOSTOS),cygwin)
> >  HOSTCFLAGS	+= -ansi
> >  endif
> > 
> > @@ -140,13 +142,13 @@ binutils-version = $(shell $(SHELL)
> > $(SRCTREE)/tools/binutils-version.sh $(AS))
> > 
> >  #
> >  # Include the make variables (CC, etc...)
> >  #
> > 
> > -AS	= $(CROSS_COMPILE)as
> > +AS	= $(CCACHE) $(CROSS_COMPILE)as
> > 
> >  # Always use GNU ld
> >  LD	= $(shell if $(CROSS_COMPILE)ld.bfd -v > /dev/null 2>&1; \
> >  
> >  		then echo "$(CROSS_COMPILE)ld.bfd"; else echo 
"$(CROSS_COMPILE)ld";
> >  		fi;)
> > 
> > -CC	= $(CROSS_COMPILE)gcc
> > +CC	= $(CCACHE) $(CROSS_COMPILE)gcc
> > 
> >  CPP	= $(CC) -E
> >  AR	= $(CROSS_COMPILE)ar
> >  NM	= $(CROSS_COMPILE)nm
> > 
> > @@ -320,7 +322,7 @@ endif
> > 
> >  ########################################################################
> >  #
> > 
> > -export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE 
\
> > +export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE
> > CCACHE \
> > 
> >  	AS LD CC CPP AR NM STRIP OBJCOPY OBJDUMP MAKE
> >  
> >  export	CONFIG_SYS_TEXT_BASE PLATFORM_CPPFLAGS PLATFORM_RELFLAGS 
CPPFLAGS
> >  CFLAGS AFLAGS
> 
> Where did this patch go? I found it useful.

It needs additional fixes, try running with MAKEALL and you will see the problem 
-- the problem is you would need separate ccache for each MAKEALL thread.

Best regards,
Marek Vasut
sun york-R58495 - Aug. 22, 2013, 3:42 a.m.
On Aug 21, 2013, at 7:51 PM, Marek Vasut wrote:

> Dear York Sun,
> 
>> On 05/20/2013 10:25 AM, Marek Vasut wrote:
>>> Prefix HOSTCC and CC with CCACHE variable to allow easy use of ccache.
>>> In case the user wants to use ccache, exporting CCACHE=ccache will do
>>> the trick. It is of course possible to either make the cross-compiler
>>> name into a shellscript which invokes the ccache and the compiler, but
>>> setting this variable makes use of ccache easier and more convenient.
>>> 
>>> Using ccache becomes convenient when using MAKEALL for large build
>>> tests, where the speedup after building the cache for the first time
>>> is about 4-6 times.
>>> 
>>> Signed-off-by: Marek Vasut <marex@denx.de>
>>> Cc: Tom Rini <trini@ti.com>
>>> 
>>> ---
>>> config.mk |    8 +++++---
>>> 
>>> 1 file changed, 5 insertions(+), 3 deletions(-)
>>> 
>>> diff --git a/config.mk b/config.mk
>>> index 1fd109f..d59ded2 100644
>>> --- a/config.mk
>>> +++ b/config.mk
>>> @@ -98,6 +98,8 @@ else
>>> 
>>> HOSTCC		= gcc
>>> endif
>>> 
>>> +HOSTCC		:= $(CCACHE) $(HOSTCC)
>>> +
>>> 
>>> ifeq ($(HOSTOS),cygwin)
>>> HOSTCFLAGS	+= -ansi
>>> endif
>>> 
>>> @@ -140,13 +142,13 @@ binutils-version = $(shell $(SHELL)
>>> $(SRCTREE)/tools/binutils-version.sh $(AS))
>>> 
>>> #
>>> # Include the make variables (CC, etc...)
>>> #
>>> 
>>> -AS	= $(CROSS_COMPILE)as
>>> +AS	= $(CCACHE) $(CROSS_COMPILE)as
>>> 
>>> # Always use GNU ld
>>> LD	= $(shell if $(CROSS_COMPILE)ld.bfd -v > /dev/null 2>&1; \
>>> 
>>> 		then echo "$(CROSS_COMPILE)ld.bfd"; else echo 
> "$(CROSS_COMPILE)ld";
>>> 		fi;)
>>> 
>>> -CC	= $(CROSS_COMPILE)gcc
>>> +CC	= $(CCACHE) $(CROSS_COMPILE)gcc
>>> 
>>> CPP	= $(CC) -E
>>> AR	= $(CROSS_COMPILE)ar
>>> NM	= $(CROSS_COMPILE)nm
>>> 
>>> @@ -320,7 +322,7 @@ endif
>>> 
>>> ########################################################################
>>> #
>>> 
>>> -export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE 
> \
>>> +export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE
>>> CCACHE \
>>> 
>>> 	AS LD CC CPP AR NM STRIP OBJCOPY OBJDUMP MAKE
>>> 
>>> export	CONFIG_SYS_TEXT_BASE PLATFORM_CPPFLAGS PLATFORM_RELFLAGS 
> CPPFLAGS
>>> CFLAGS AFLAGS
>> 
>> Where did this patch go? I found it useful.
> 
> It needs additional fixes, try running with MAKEALL and you will see the problem 
> -- the problem is you would need separate ccache for each MAKEALL thread.


I didn't use this patch but I modified config.mk as this patch did. MAKEALL works fine for "-a powerpc". It cuts my compiling time more than half for 660+ boards.

York
Marek Vasut - Aug. 22, 2013, 5:02 a.m.
Dear sun york-R58495,

> On Aug 21, 2013, at 7:51 PM, Marek Vasut wrote:
> > Dear York Sun,
> > 
> >> On 05/20/2013 10:25 AM, Marek Vasut wrote:
> >>> Prefix HOSTCC and CC with CCACHE variable to allow easy use of ccache.
> >>> In case the user wants to use ccache, exporting CCACHE=ccache will do
> >>> the trick. It is of course possible to either make the cross-compiler
> >>> name into a shellscript which invokes the ccache and the compiler, but
> >>> setting this variable makes use of ccache easier and more convenient.
> >>> 
> >>> Using ccache becomes convenient when using MAKEALL for large build
> >>> tests, where the speedup after building the cache for the first time
> >>> is about 4-6 times.
> >>> 
> >>> Signed-off-by: Marek Vasut <marex@denx.de>
> >>> Cc: Tom Rini <trini@ti.com>
> >>> 
> >>> ---
> >>> config.mk |    8 +++++---
> >>> 
> >>> 1 file changed, 5 insertions(+), 3 deletions(-)
> >>> 
> >>> diff --git a/config.mk b/config.mk
> >>> index 1fd109f..d59ded2 100644
> >>> --- a/config.mk
> >>> +++ b/config.mk
> >>> @@ -98,6 +98,8 @@ else
> >>> 
> >>> HOSTCC		= gcc
> >>> endif
> >>> 
> >>> +HOSTCC		:= $(CCACHE) $(HOSTCC)
> >>> +
> >>> 
> >>> ifeq ($(HOSTOS),cygwin)
> >>> HOSTCFLAGS	+= -ansi
> >>> endif
> >>> 
> >>> @@ -140,13 +142,13 @@ binutils-version = $(shell $(SHELL)
> >>> $(SRCTREE)/tools/binutils-version.sh $(AS))
> >>> 
> >>> #
> >>> # Include the make variables (CC, etc...)
> >>> #
> >>> 
> >>> -AS	= $(CROSS_COMPILE)as
> >>> +AS	= $(CCACHE) $(CROSS_COMPILE)as
> >>> 
> >>> # Always use GNU ld
> >>> LD	= $(shell if $(CROSS_COMPILE)ld.bfd -v > /dev/null 2>&1; \
> >>> 
> >>> 		then echo "$(CROSS_COMPILE)ld.bfd"; else echo
> > 
> > "$(CROSS_COMPILE)ld";
> > 
> >>> 		fi;)
> >>> 
> >>> -CC	= $(CROSS_COMPILE)gcc
> >>> +CC	= $(CCACHE) $(CROSS_COMPILE)gcc
> >>> 
> >>> CPP	= $(CC) -E
> >>> AR	= $(CROSS_COMPILE)ar
> >>> NM	= $(CROSS_COMPILE)nm
> >>> 
> >>> @@ -320,7 +322,7 @@ endif
> >>> 
> >>> #######################################################################
> >>> # #
> >>> 
> >>> -export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE
> > 
> > \
> > 
> >>> +export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE
> >>> CCACHE \
> >>> 
> >>> 	AS LD CC CPP AR NM STRIP OBJCOPY OBJDUMP MAKE
> >>> 
> >>> export	CONFIG_SYS_TEXT_BASE PLATFORM_CPPFLAGS PLATFORM_RELFLAGS
> > 
> > CPPFLAGS
> > 
> >>> CFLAGS AFLAGS
> >> 
> >> Where did this patch go? I found it useful.
> > 
> > It needs additional fixes, try running with MAKEALL and you will see the
> > problem -- the problem is you would need separate ccache for each
> > MAKEALL thread.
> 
> I didn't use this patch but I modified config.mk as this patch did. MAKEALL
> works fine for "-a powerpc". It cuts my compiling time more than half for
> 660+ boards.

That is still poor, it should be much faster. If you use separate ccache for 
each board, then it will be _much_ more performant.

The problem is that when rebuilding all of those 680 configurations, the cached 
files get replaced by ones based on different board config all the time => you 
need to rebuild them => you loose performance.

Best regards,
Marek Vasut
sun york-R58495 - Aug. 22, 2013, 5:45 a.m.
On Aug 21, 2013, at 10:02 PM, Marek Vasut wrote:

> Dear sun york-R58495,
> 
>> On Aug 21, 2013, at 7:51 PM, Marek Vasut wrote:
>>> Dear York Sun,
>>> 
>>>> On 05/20/2013 10:25 AM, Marek Vasut wrote:
>>>>> Prefix HOSTCC and CC with CCACHE variable to allow easy use of ccache.
>>>>> In case the user wants to use ccache, exporting CCACHE=ccache will do
>>>>> the trick. It is of course possible to either make the cross-compiler
>>>>> name into a shellscript which invokes the ccache and the compiler, but
>>>>> setting this variable makes use of ccache easier and more convenient.
>>>>> 
>>>>> Using ccache becomes convenient when using MAKEALL for large build
>>>>> tests, where the speedup after building the cache for the first time
>>>>> is about 4-6 times.
>>>>> 
>>>>> Signed-off-by: Marek Vasut <marex@denx.de>
>>>>> Cc: Tom Rini <trini@ti.com>
>>>>> 
>>>>> ---
>>>>> config.mk |    8 +++++---
>>>>> 
>>>>> 1 file changed, 5 insertions(+), 3 deletions(-)
>>>>> 
>>>>> diff --git a/config.mk b/config.mk
>>>>> index 1fd109f..d59ded2 100644
>>>>> --- a/config.mk
>>>>> +++ b/config.mk
>>>>> @@ -98,6 +98,8 @@ else
>>>>> 
>>>>> HOSTCC		= gcc
>>>>> endif
>>>>> 
>>>>> +HOSTCC		:= $(CCACHE) $(HOSTCC)
>>>>> +
>>>>> 
>>>>> ifeq ($(HOSTOS),cygwin)
>>>>> HOSTCFLAGS	+= -ansi
>>>>> endif
>>>>> 
>>>>> @@ -140,13 +142,13 @@ binutils-version = $(shell $(SHELL)
>>>>> $(SRCTREE)/tools/binutils-version.sh $(AS))
>>>>> 
>>>>> #
>>>>> # Include the make variables (CC, etc...)
>>>>> #
>>>>> 
>>>>> -AS	= $(CROSS_COMPILE)as
>>>>> +AS	= $(CCACHE) $(CROSS_COMPILE)as
>>>>> 
>>>>> # Always use GNU ld
>>>>> LD	= $(shell if $(CROSS_COMPILE)ld.bfd -v > /dev/null 2>&1; \
>>>>> 
>>>>> 		then echo "$(CROSS_COMPILE)ld.bfd"; else echo
>>> 
>>> "$(CROSS_COMPILE)ld";
>>> 
>>>>> 		fi;)
>>>>> 
>>>>> -CC	= $(CROSS_COMPILE)gcc
>>>>> +CC	= $(CCACHE) $(CROSS_COMPILE)gcc
>>>>> 
>>>>> CPP	= $(CC) -E
>>>>> AR	= $(CROSS_COMPILE)ar
>>>>> NM	= $(CROSS_COMPILE)nm
>>>>> 
>>>>> @@ -320,7 +322,7 @@ endif
>>>>> 
>>>>> #######################################################################
>>>>> # #
>>>>> 
>>>>> -export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE
>>> 
>>> \
>>> 
>>>>> +export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE
>>>>> CCACHE \
>>>>> 
>>>>> 	AS LD CC CPP AR NM STRIP OBJCOPY OBJDUMP MAKE
>>>>> 
>>>>> export	CONFIG_SYS_TEXT_BASE PLATFORM_CPPFLAGS PLATFORM_RELFLAGS
>>> 
>>> CPPFLAGS
>>> 
>>>>> CFLAGS AFLAGS
>>>> 
>>>> Where did this patch go? I found it useful.
>>> 
>>> It needs additional fixes, try running with MAKEALL and you will see the
>>> problem -- the problem is you would need separate ccache for each
>>> MAKEALL thread.
>> 
>> I didn't use this patch but I modified config.mk as this patch did. MAKEALL
>> works fine for "-a powerpc". It cuts my compiling time more than half for
>> 660+ boards.
> 
> That is still poor, it should be much faster. If you use separate ccache for 
> each board, then it will be _much_ more performant.
> 
> The problem is that when rebuilding all of those 680 configurations, the cached 
> files get replaced by ones based on different board config all the time => you 
> need to rebuild them => you loose performance.
> 

I kind of get it. I have to increase my ccache size a lot (more than 2GB) to get consistent cache hit. I thought that was because I was using out-of-tree build when setting BUILD_NBUILDS. For the first time I run MAKEALL with ccache, it was completely miss. I mean zero hit. It would be nice to be able hit the cache. I was read the ccache document to understand how the path is involved when calculating the hash. How do you plan to make it work?

York
sun york-R58495 - Aug. 22, 2013, 5:54 a.m.
On Aug 21, 2013, at 10:45 PM, sun york-R58495 wrote:

> 
> On Aug 21, 2013, at 10:02 PM, Marek Vasut wrote:
> 
>> Dear sun york-R58495,
>> 
>>> On Aug 21, 2013, at 7:51 PM, Marek Vasut wrote:
>>>> Dear York Sun,
>>>> 
>>>>> On 05/20/2013 10:25 AM, Marek Vasut wrote:
>>>>>> Prefix HOSTCC and CC with CCACHE variable to allow easy use of ccache.
>>>>>> In case the user wants to use ccache, exporting CCACHE=ccache will do
>>>>>> the trick. It is of course possible to either make the cross-compiler
>>>>>> name into a shellscript which invokes the ccache and the compiler, but
>>>>>> setting this variable makes use of ccache easier and more convenient.
>>>>>> 
>>>>>> Using ccache becomes convenient when using MAKEALL for large build
>>>>>> tests, where the speedup after building the cache for the first time
>>>>>> is about 4-6 times.
>>>>>> 
>>>>>> Signed-off-by: Marek Vasut <marex@denx.de>
>>>>>> Cc: Tom Rini <trini@ti.com>
>>>>>> 
>>>>>> ---
>>>>>> config.mk |    8 +++++---
>>>>>> 
>>>>>> 1 file changed, 5 insertions(+), 3 deletions(-)
>>>>>> 
>>>>>> diff --git a/config.mk b/config.mk
>>>>>> index 1fd109f..d59ded2 100644
>>>>>> --- a/config.mk
>>>>>> +++ b/config.mk
>>>>>> @@ -98,6 +98,8 @@ else
>>>>>> 
>>>>>> HOSTCC		= gcc
>>>>>> endif
>>>>>> 
>>>>>> +HOSTCC		:= $(CCACHE) $(HOSTCC)
>>>>>> +
>>>>>> 
>>>>>> ifeq ($(HOSTOS),cygwin)
>>>>>> HOSTCFLAGS	+= -ansi
>>>>>> endif
>>>>>> 
>>>>>> @@ -140,13 +142,13 @@ binutils-version = $(shell $(SHELL)
>>>>>> $(SRCTREE)/tools/binutils-version.sh $(AS))
>>>>>> 
>>>>>> #
>>>>>> # Include the make variables (CC, etc...)
>>>>>> #
>>>>>> 
>>>>>> -AS	= $(CROSS_COMPILE)as
>>>>>> +AS	= $(CCACHE) $(CROSS_COMPILE)as
>>>>>> 
>>>>>> # Always use GNU ld
>>>>>> LD	= $(shell if $(CROSS_COMPILE)ld.bfd -v > /dev/null 2>&1; \
>>>>>> 
>>>>>> 		then echo "$(CROSS_COMPILE)ld.bfd"; else echo
>>>> 
>>>> "$(CROSS_COMPILE)ld";
>>>> 
>>>>>> 		fi;)
>>>>>> 
>>>>>> -CC	= $(CROSS_COMPILE)gcc
>>>>>> +CC	= $(CCACHE) $(CROSS_COMPILE)gcc
>>>>>> 
>>>>>> CPP	= $(CC) -E
>>>>>> AR	= $(CROSS_COMPILE)ar
>>>>>> NM	= $(CROSS_COMPILE)nm
>>>>>> 
>>>>>> @@ -320,7 +322,7 @@ endif
>>>>>> 
>>>>>> #######################################################################
>>>>>> # #
>>>>>> 
>>>>>> -export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE
>>>> 
>>>> \
>>>> 
>>>>>> +export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE
>>>>>> CCACHE \
>>>>>> 
>>>>>> 	AS LD CC CPP AR NM STRIP OBJCOPY OBJDUMP MAKE
>>>>>> 
>>>>>> export	CONFIG_SYS_TEXT_BASE PLATFORM_CPPFLAGS PLATFORM_RELFLAGS
>>>> 
>>>> CPPFLAGS
>>>> 
>>>>>> CFLAGS AFLAGS
>>>>> 
>>>>> Where did this patch go? I found it useful.
>>>> 
>>>> It needs additional fixes, try running with MAKEALL and you will see the
>>>> problem -- the problem is you would need separate ccache for each
>>>> MAKEALL thread.
>>> 
>>> I didn't use this patch but I modified config.mk as this patch did. MAKEALL
>>> works fine for "-a powerpc". It cuts my compiling time more than half for
>>> 660+ boards.
>> 
>> That is still poor, it should be much faster. If you use separate ccache for 
>> each board, then it will be _much_ more performant.
>> 
>> The problem is that when rebuilding all of those 680 configurations, the cached 
>> files get replaced by ones based on different board config all the time => you 
>> need to rebuild them => you loose performance.
>> 
> 
> I kind of get it. I have to increase my ccache size a lot (more than 2GB) to get consistent cache hit. I thought that was because I was using out-of-tree build when setting BUILD_NBUILDS. For the first time I run MAKEALL with ccache, it was completely miss. I mean zero hit. It would be nice to be able hit the cache. I was read the ccache document to understand how the path is involved when calculating the hash. How do you plan to make it work?
> 
I forgot to mention, if the ccache size is at default (1GB), I don't see any performance improvement by using ccache. I think that's what you meant the cached files get replaced. I don't understand what you mean to use separated ccache for each board. Would it be equivalent to have a big cache? I was compiling with and without BUILD_NBUILDS, and my cache size is more than 3GB now. I could see the improvement by 2x~3x faster, but not more. 

York
Marek Vasut - Aug. 22, 2013, 7:36 p.m.
Dear sun york-R58495,

> On Aug 21, 2013, at 10:45 PM, sun york-R58495 wrote:
> > On Aug 21, 2013, at 10:02 PM, Marek Vasut wrote:
> >> Dear sun york-R58495,
> >> 
> >>> On Aug 21, 2013, at 7:51 PM, Marek Vasut wrote:
> >>>> Dear York Sun,
> >>>> 
> >>>>> On 05/20/2013 10:25 AM, Marek Vasut wrote:
> >>>>>> Prefix HOSTCC and CC with CCACHE variable to allow easy use of
> >>>>>> ccache. In case the user wants to use ccache, exporting
> >>>>>> CCACHE=ccache will do the trick. It is of course possible to either
> >>>>>> make the cross-compiler name into a shellscript which invokes the
> >>>>>> ccache and the compiler, but setting this variable makes use of
> >>>>>> ccache easier and more convenient.
> >>>>>> 
> >>>>>> Using ccache becomes convenient when using MAKEALL for large build
> >>>>>> tests, where the speedup after building the cache for the first time
> >>>>>> is about 4-6 times.
> >>>>>> 
> >>>>>> Signed-off-by: Marek Vasut <marex@denx.de>
> >>>>>> Cc: Tom Rini <trini@ti.com>
> >>>>>> 
> >>>>>> ---
> >>>>>> config.mk |    8 +++++---
> >>>>>> 
> >>>>>> 1 file changed, 5 insertions(+), 3 deletions(-)
> >>>>>> 
> >>>>>> diff --git a/config.mk b/config.mk
> >>>>>> index 1fd109f..d59ded2 100644
> >>>>>> --- a/config.mk
> >>>>>> +++ b/config.mk
> >>>>>> @@ -98,6 +98,8 @@ else
> >>>>>> 
> >>>>>> HOSTCC		= gcc
> >>>>>> endif
> >>>>>> 
> >>>>>> +HOSTCC		:= $(CCACHE) $(HOSTCC)
> >>>>>> +
> >>>>>> 
> >>>>>> ifeq ($(HOSTOS),cygwin)
> >>>>>> HOSTCFLAGS	+= -ansi
> >>>>>> endif
> >>>>>> 
> >>>>>> @@ -140,13 +142,13 @@ binutils-version = $(shell $(SHELL)
> >>>>>> $(SRCTREE)/tools/binutils-version.sh $(AS))
> >>>>>> 
> >>>>>> #
> >>>>>> # Include the make variables (CC, etc...)
> >>>>>> #
> >>>>>> 
> >>>>>> -AS	= $(CROSS_COMPILE)as
> >>>>>> +AS	= $(CCACHE) $(CROSS_COMPILE)as
> >>>>>> 
> >>>>>> # Always use GNU ld
> >>>>>> LD	= $(shell if $(CROSS_COMPILE)ld.bfd -v > /dev/null 2>&1; \
> >>>>>> 
> >>>>>> 		then echo "$(CROSS_COMPILE)ld.bfd"; else echo
> >>>> 
> >>>> "$(CROSS_COMPILE)ld";
> >>>> 
> >>>>>> 		fi;)
> >>>>>> 
> >>>>>> -CC	= $(CROSS_COMPILE)gcc
> >>>>>> +CC	= $(CCACHE) $(CROSS_COMPILE)gcc
> >>>>>> 
> >>>>>> CPP	= $(CC) -E
> >>>>>> AR	= $(CROSS_COMPILE)ar
> >>>>>> NM	= $(CROSS_COMPILE)nm
> >>>>>> 
> >>>>>> @@ -320,7 +322,7 @@ endif
> >>>>>> 
> >>>>>> ####################################################################
> >>>>>> ### # #
> >>>>>> 
> >>>>>> -export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP
> >>>>>> CROSS_COMPILE
> >>>> 
> >>>> \
> >>>> 
> >>>>>> +export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP
> >>>>>> CROSS_COMPILE CCACHE \
> >>>>>> 
> >>>>>> 	AS LD CC CPP AR NM STRIP OBJCOPY OBJDUMP MAKE
> >>>>>> 
> >>>>>> export	CONFIG_SYS_TEXT_BASE PLATFORM_CPPFLAGS PLATFORM_RELFLAGS
> >>>> 
> >>>> CPPFLAGS
> >>>> 
> >>>>>> CFLAGS AFLAGS
> >>>>> 
> >>>>> Where did this patch go? I found it useful.
> >>>> 
> >>>> It needs additional fixes, try running with MAKEALL and you will see
> >>>> the problem -- the problem is you would need separate ccache for each
> >>>> MAKEALL thread.
> >>> 
> >>> I didn't use this patch but I modified config.mk as this patch did.
> >>> MAKEALL works fine for "-a powerpc". It cuts my compiling time more
> >>> than half for 660+ boards.
> >> 
> >> That is still poor, it should be much faster. If you use separate ccache
> >> for each board, then it will be _much_ more performant.
> >> 
> >> The problem is that when rebuilding all of those 680 configurations, the
> >> cached files get replaced by ones based on different board config all
> >> the time => you need to rebuild them => you loose performance.
> > 
> > I kind of get it. I have to increase my ccache size a lot (more than 2GB)
> > to get consistent cache hit. I thought that was because I was using
> > out-of-tree build when setting BUILD_NBUILDS. For the first time I run
> > MAKEALL with ccache, it was completely miss. I mean zero hit. It would
> > be nice to be able hit the cache. I was read the ccache document to
> > understand how the path is involved when calculating the hash. How do
> > you plan to make it work?
> 
> I forgot to mention, if the ccache size is at default (1GB), I don't see
> any performance improvement by using ccache. I think that's what you meant
> the cached files get replaced. I don't understand what you mean to use
> separated ccache for each board. Would it be equivalent to have a big
> cache? I was compiling with and without BUILD_NBUILDS, and my cache size
> is more than 3GB now. I could see the improvement by 2x~3x faster, but not
> more.

There is an env variable to configure separate ccache cache dir , so just by 
setting that. But then , when each build ends, you would need to clean it up 
somehow. It was mentioned in the discussion with the patch. You can try working 
on this some more and post a patch, then we can talk about further forging of 
this.

Best regards,
Marek Vasut
York Sun - Aug. 23, 2013, 12:05 a.m.
On 08/22/2013 12:36 PM, Marek Vasut wrote:
> 
> There is an env variable to configure separate ccache cache dir , so just by 
> setting that. But then , when each build ends, you would need to clean it up 
> somehow. It was mentioned in the discussion with the patch. You can try working 
> on this some more and post a patch, then we can talk about further forging of 
> this.
> 

I fixed the 2nd patch and I am running MAKEALL with individual board
folder for ccache. The compiling time for the first run on my laptop is
56 minutes. The 2nd run is 23 minutes. About the same improvement if
using a big unified cache for all boards. By the way, each board cache
is about 7~8MB.

You set my expectation high. I was hoping to get 10x or more improvement.

York
Marek Vasut - Aug. 23, 2013, 3:05 a.m.
Dear York Sun,

> On 08/22/2013 12:36 PM, Marek Vasut wrote:
> > There is an env variable to configure separate ccache cache dir , so just
> > by setting that. But then , when each build ends, you would need to
> > clean it up somehow. It was mentioned in the discussion with the patch.
> > You can try working on this some more and post a patch, then we can talk
> > about further forging of this.
> 
> I fixed the 2nd patch and I am running MAKEALL with individual board
> folder for ccache. The compiling time for the first run on my laptop is
> 56 minutes. The 2nd run is 23 minutes. About the same improvement if
> using a big unified cache for all boards. By the way, each board cache
> is about 7~8MB.
> 
> You set my expectation high. I was hoping to get 10x or more improvement.

It should be more, try checking if there is no bottleneck.

Best regards,
Marek Vasut
York Sun - Aug. 23, 2013, 8:19 p.m.
On 08/22/2013 08:05 PM, Marek Vasut wrote:
> Dear York Sun,
> 
>> On 08/22/2013 12:36 PM, Marek Vasut wrote:
>>> There is an env variable to configure separate ccache cache dir , so just
>>> by setting that. But then , when each build ends, you would need to
>>> clean it up somehow. It was mentioned in the discussion with the patch.
>>> You can try working on this some more and post a patch, then we can talk
>>> about further forging of this.
>>
>> I fixed the 2nd patch and I am running MAKEALL with individual board
>> folder for ccache. The compiling time for the first run on my laptop is
>> 56 minutes. The 2nd run is 23 minutes. About the same improvement if
>> using a big unified cache for all boards. By the way, each board cache
>> is about 7~8MB.
>>
>> You set my expectation high. I was hoping to get 10x or more improvement.
> 
> It should be more, try checking if there is no bottleneck.
> 

I can send you the patch. Will you be able to test?

York

Patch

diff --git a/config.mk b/config.mk
index 1fd109f..d59ded2 100644
--- a/config.mk
+++ b/config.mk
@@ -98,6 +98,8 @@  else
 HOSTCC		= gcc
 endif
 
+HOSTCC		:= $(CCACHE) $(HOSTCC)
+
 ifeq ($(HOSTOS),cygwin)
 HOSTCFLAGS	+= -ansi
 endif
@@ -140,13 +142,13 @@  binutils-version = $(shell $(SHELL) $(SRCTREE)/tools/binutils-version.sh $(AS))
 #
 # Include the make variables (CC, etc...)
 #
-AS	= $(CROSS_COMPILE)as
+AS	= $(CCACHE) $(CROSS_COMPILE)as
 
 # Always use GNU ld
 LD	= $(shell if $(CROSS_COMPILE)ld.bfd -v > /dev/null 2>&1; \
 		then echo "$(CROSS_COMPILE)ld.bfd"; else echo "$(CROSS_COMPILE)ld"; fi;)
 
-CC	= $(CROSS_COMPILE)gcc
+CC	= $(CCACHE) $(CROSS_COMPILE)gcc
 CPP	= $(CC) -E
 AR	= $(CROSS_COMPILE)ar
 NM	= $(CROSS_COMPILE)nm
@@ -320,7 +322,7 @@  endif
 
 #########################################################################
 
-export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE \
+export	HOSTCC HOSTCFLAGS HOSTLDFLAGS PEDCFLAGS HOSTSTRIP CROSS_COMPILE CCACHE \
 	AS LD CC CPP AR NM STRIP OBJCOPY OBJDUMP MAKE
 export	CONFIG_SYS_TEXT_BASE PLATFORM_CPPFLAGS PLATFORM_RELFLAGS CPPFLAGS CFLAGS AFLAGS