kernel_optimize_test/arch/x86_64/Makefile
Arjan van de Ven 4bdc3b7f1b [PATCH] x86_64: Basic reorder infrastructure
This patch puts the infrastructure in place to allow for a reordering of
functions based inside the vmlinux. The general idea is that it is possible
to put all "common" functions into the first 2Mb of the code, so that they
are covered by one TLB entry. This as opposed to the current situation where
a typical vmlinux covers about 3.5Mb (on x86-64) and thus 2 TLB entries.

This is done by enabling the -ffunction-sections flag in gcc, which puts
each function in its own ELF section, so that the linker can then order them
in a way defined by the linker script.

As per previous discussions, Linus said he wanted a "static" list for this,
eg a list provided by the kernel tarbal, so that most people have the same
ordering at least. A script is provided to create this list based on
readprofile(1) output. The included list is provisional, and entirely biased
on my own testbox and me running a few kernel compiles and some other
things.

I think that to get to a better list we need to invite people to submit
their own profiles, and somehow add those all up and base the final list on
that. I'm willing to do that effort if this is ends up being the prefered
approach. Such an effort probably needs to be repeated like once a year or
so to adopt to the changing nature of the kernel.

Made it a CONFIG with default n because it increases link times
dramatically.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 09:10:56 -08:00

110 lines
3.4 KiB
Makefile

#
# x86_64/Makefile
#
# This file is included by the global makefile so that you can add your own
# architecture-specific flags and dependencies. Remember to do have actions
# for "archclean" and "archdep" for cleaning up and making dependencies for
# this architecture
#
# This file is subject to the terms and conditions of the GNU General Public
# License. See the file "COPYING" in the main directory of this archive
# for more details.
#
# Copyright (C) 1994 by Linus Torvalds
#
# 19990713 Artur Skawina <skawina@geocities.com>
# Added '-march' and '-mpreferred-stack-boundary' support
# 20000913 Pavel Machek <pavel@suse.cz>
# Converted for x86_64 architecture
# 20010105 Andi Kleen, add IA32 compiler.
# ....and later removed it again....
#
# $Id: Makefile,v 1.31 2002/03/22 15:56:07 ak Exp $
LDFLAGS := -m elf_x86_64
OBJCOPYFLAGS := -O binary -R .note -R .comment -S
LDFLAGS_vmlinux :=
CHECKFLAGS += -D__x86_64__ -m64
cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8)
cflags-$(CONFIG_MPSC) += $(call cc-option,-march=nocona)
cflags-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=generic)
CFLAGS += $(cflags-y)
CFLAGS += -m64
CFLAGS += -mno-red-zone
CFLAGS += -mcmodel=kernel
CFLAGS += -pipe
cflags-$(CONFIG_REORDER) += -ffunction-sections
# this makes reading assembly source easier, but produces worse code
# actually it makes the kernel smaller too.
CFLAGS += -fno-reorder-blocks
CFLAGS += -Wno-sign-compare
ifneq ($(CONFIG_UNWIND_INFO),y)
CFLAGS += -fno-asynchronous-unwind-tables
endif
ifneq ($(CONFIG_DEBUG_INFO),y)
# -fweb shrinks the kernel a bit, but the difference is very small
# it also messes up debugging, so don't use it for now.
#CFLAGS += $(call cc-option,-fweb)
endif
# -funit-at-a-time shrinks the kernel .text considerably
# unfortunately it makes reading oopses harder.
CFLAGS += $(call cc-option,-funit-at-a-time)
# prevent gcc from generating any FP code by mistake
CFLAGS += $(call cc-option,-mno-sse -mno-mmx -mno-sse2 -mno-3dnow,)
AFLAGS += -m64
head-y := arch/x86_64/kernel/head.o arch/x86_64/kernel/head64.o arch/x86_64/kernel/init_task.o
libs-y += arch/x86_64/lib/
core-y += arch/x86_64/kernel/ \
arch/x86_64/mm/ \
arch/x86_64/crypto/
core-$(CONFIG_IA32_EMULATION) += arch/x86_64/ia32/
drivers-$(CONFIG_PCI) += arch/x86_64/pci/
drivers-$(CONFIG_OPROFILE) += arch/x86_64/oprofile/
boot := arch/x86_64/boot
PHONY += bzImage bzlilo install archmrproper \
fdimage fdimage144 fdimage288 archclean
#Default target when executing "make"
all: bzImage
BOOTIMAGE := arch/x86_64/boot/bzImage
KBUILD_IMAGE := $(BOOTIMAGE)
bzImage: vmlinux
$(Q)$(MAKE) $(build)=$(boot) $(BOOTIMAGE)
bzlilo: vmlinux
$(Q)$(MAKE) $(build)=$(boot) BOOTIMAGE=$(BOOTIMAGE) zlilo
bzdisk: vmlinux
$(Q)$(MAKE) $(build)=$(boot) BOOTIMAGE=$(BOOTIMAGE) zdisk
fdimage fdimage144 fdimage288: vmlinux
$(Q)$(MAKE) $(build)=$(boot) BOOTIMAGE=$(BOOTIMAGE) $@
install:
$(Q)$(MAKE) $(build)=$(boot) BOOTIMAGE=$(BOOTIMAGE) $@
archclean:
$(Q)$(MAKE) $(clean)=$(boot)
define archhelp
echo '* bzImage - Compressed kernel image (arch/$(ARCH)/boot/bzImage)'
echo ' install - Install kernel using'
echo ' (your) ~/bin/installkernel or'
echo ' (distribution) /sbin/installkernel or'
echo ' install to $$(INSTALL_PATH) and run lilo'
endef
CLEAN_FILES += arch/$(ARCH)/boot/fdimage arch/$(ARCH)/boot/mtools.conf