[U-Boot] [U-Boot, 1/2] common: Add CCACHE variable to allow use of ccache
Marek Vasut
marex at denx.de
Thu Aug 22 07:02:39 CEST 2013
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 at denx.de>
> >>> Cc: Tom Rini <trini at 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
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