While changing our build system over to use the headers_install target
as part of our klibc build, the following message started showing up in
our logs:
make[2]: `scripts/unifdef' is up to date.
It turns out that the build blindly invokes a recursive make on this
target, which causes make to emit this message when the target is
already up to date. This isn't seen for most targets as the rest of the
build relies primarily on the default target and on PHONY targets when
invoking make recursively.
Silence the above message when building unifdef as part of
headers_install by hiding it behind a new PHONY target called
"build_unifdef" that has an empty recipe.
Signed-off-by: Mike Waychison <mikew@google.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Add a 'W=1' Makefile switch which adds additional checking per build
object.
The idea behind this option is targeted at developers who, in the
process of writing their code, want to do the occasional
make W=1 [target.o]
and let gcc do more extensive code checking for them. Then, they
could eyeball the output for valid gcc warnings about various
bugs/discrepancies which are not reported during the normal build
process.
For more background information and a use case, read through this
thread: http://marc.info/?l=kernel-janitors&m=129802065918147&w=2
Cc: Michal Marek <mmarek@suse.cz>
Cc: linux-kbuild@vger.kernel.org
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Michal Marek <mmarek@suse.cz>
GNU GLOBAL (http://www.gnu.org/software/global/) is a source code tagging system
It is really cheap to support it in kbuild system.
Signed-off-by: Jianbin Kang <kjbmail@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
If you try to build a kernel with KCONFIG_CONFIG set (to a value
not equal to .config) and that config sets CONFIG_IKCONFIG then the
build will fail with:
make[1]: *** No rule to make target `.config', needed by \
`kernel/config_data.gz'. Stop.
because the kernel/Makefile contains a direct reference to .config.
This issue has been present since the introduction of KCONFIG_CONFIG
in 14cdd3c402.
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
CC: Roman Zippel <zippel@linux-m68k.org>
CC: Michal Marek <mmarek@suse.cz>
Reviewed-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Add 'sparc32' ARCH target to test all{yes,mod}config for 32-bit build.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The config option used by archs to let the build system know that
the C version of the recordmcount works for said arch is currently
called HAVE_C_MCOUNT_RECORD which enables BUILD_C_RECORDMCOUNT. To
be more consistent with the name that all archs may use, it has been
renamed to HAVE_C_RECORDMCOUNT. This will be less confusing since
we are building a C recordmcount and not a mcount_record.
Suggested-by: Ingo Molnar <mingo@elte.hu>
Cc: <linux-arch@vger.kernel.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: linux-kbuild@vger.kernel.org
Cc: John Reiser <jreiser@bitwagon.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This patch adds the support for the C version of recordmcount and
compile times show ~ 12% improvement.
After verifying this works, other archs can add:
HAVE_C_MCOUNT_RECORD
in its Kconfig and it will use the C version of recordmcount
instead of the perl version.
Cc: <linux-arch@vger.kernel.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: linux-kbuild@vger.kernel.org
Cc: John Reiser <jreiser@bitwagon.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
base patch to implement 'jump labeling'. Based on a new 'asm goto' inline
assembly gcc mechanism, we can now branch to labels from an 'asm goto'
statment. This allows us to create a 'no-op' fastpath, which can subsequently
be patched with a jump to the slowpath code. This is useful for code which
might be rarely used, but which we'd like to be able to call, if needed.
Tracepoints are the current usecase that these are being implemented for.
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <ee8b3595967989fdaf84e698dc7447d315ce972a.1284733808.git.jbaron@redhat.com>
[ cleaned up some formating ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
With current gcc, compiling with both -pg and -fomit-frame-pointer is
not allowed. However, -pg can be used to build without actually
specifying -fno-omit-frame-pointer, upon which the default behaviour
for the target will be used.
On ARM, it is not possible to build a Thumb-2 kernel with
-fno-omit-frame-pointer (FRAME_POINTERS depends on !THUMB2_KERNEL). In
order to support ftrace for Thumb-2, we need to be able to allow a
combination of FUNCTION_TRACER and !FRAME_POINTER. We do this by
omitting -fomit-frame-pointer if ftrace is enabled.
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Brice reported that 'kernelrelease' has a dependence on include/config/kernel.release,
causes this file to be regenerated every time when invoke it. It doesn't have to.
Reported-by: Brice Goglin <Brice.Goglin@inria.fr>
Tested-by: Brice Goglin <Brice.Goglin@inria.fr>
Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
It is now possible to assign options to AS and CC
on the command line - which is only used for built-in code.
{A,C}FLAGS_KERNEL was used both in the top-level Makefile
in the arch makefiles, thus users had no way to specify
additional options to AS, CC without overriding
the original value.
Introduce a new set of variables KBUILD_{A,C}FLAGS_KERNEL
that is used by arch specific files and free up
{A,C}FLAGS_KERNEL so they can be assigned on
the command line.
All arch Makefiles that used the old variables has been updated.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
It is now possible to assign options to AS, CC and LD
on the command line - which is only used when building modules.
{A,C,LD}FLAGS_MODULE was all used both in the top-level Makefile
in the arch makefiles, thus users had no way to specify
additional options to AS, CC, LD when building modules
without overriding the original value.
Introduce a new set of variables KBUILD_{A,C,LD}FLAGS_MODULE
that is used by arch specific files and free up
{A,C,LD}FLAGS_MODULE so they can be assigned on
the command line.
All arch Makefiles that used the old variables has been updated.
Note: Previously we had a MODFLAGS variable for both
AS and CC. But in favour of consistency this was dropped.
So in some cases arch Makefile has one assignmnet replaced by
two assignmnets.
Note2: MODFLAGS was not documented and is dropped
without any notice. I do not expect much/any breakage
from this.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Acked-by: Mike Frysinger <vapier@gentoo.org> [blackfin]
Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> [avr32]
Signed-off-by: Michal Marek <mmarek@suse.cz>
Newer gcc has a -femit-struct-debug-baseonly option that dramatically
reduces the size of object files with debug info. What it does
is to only emit type information for structures when the structures
are defined in the same file or in a header file.
This means the type information for most headers are not included.
This is not good when the type information is actually
needed (e.g. with kgdb or systemtap)
But often kernel hackers only care about line numbers and don't
need all the type information anyways. In this case setting
the option can be a big win:
A build dir for a specific x86-64 configuration with gcc 4.5
shrunk from 2.3G to 1.2G. The compilation was also nearly a minute
faster.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
[mmarek: reformatted help text]
Signed-off-by: Michal Marek <mmarek@suse.cz>
Commit 0a564b2 broke LOCALVERSION for O=... builds. Ouch.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-and-tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Peter Anvin <hpa@zytor.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds