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8b4169f1c9
Northstar SoCs have pretty small CPU caches and their performance is
heavily affected by cache hits & misses. It means that all kind of
random code changes can affect performance as they often reorganize
(change alignment & possibly reorder) kernel symbols.
It was discussed in ARM / net mailinglists:
1. ARM router NAT performance affected by random/unrelated commits [1] [2]
2. Optimizing kernel compilation / alignments for network performance [3] [4]
It seems that -falign-functions can be used as a partial workaround. It
doesn't solve all cases (e.g. documented watchdog one [5]) but it surely
helps with many of them.
A complete long term solution may be PGO (profile-guided optimization)
but it isn't available at this point.
[1] https://lkml.org/lkml/2019/5/21/349
[2] https://www.spinics.net/lists/linux-block/msg40624.html
[3] https://lore.kernel.org/linux-arm-kernel/066fc320-dc04-11a4-476e-b0d11f3b17e6@gmail.com/T/
[4] https://www.spinics.net/lists/netdev/msg816103.html
[5] http://lists.openwrt.org/pipermail/openwrt-devel/2022-July/038989.html
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
(cherry picked from commit abc5b28db1)
144 lines
4.5 KiB
Plaintext
144 lines
4.5 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0-only
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#
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# Copyright (C) 2006-2013 OpenWrt.org
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menuconfig DEVEL
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bool "Advanced configuration options (for developers)"
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default n
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config BROKEN
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bool "Show broken platforms / packages / devices" if DEVEL
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default n
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config BINARY_FOLDER
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string "Binary folder" if DEVEL
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default ""
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help
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Store built firmware images and filesystem images in this directory.
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If not set, uses './bin/$(BOARD)'
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config DOWNLOAD_FOLDER
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string "Download folder" if DEVEL
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default ""
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help
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Store downloaded source bundles in this directory.
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If not set then defaults to './dl', which is removed by operations such as
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'git clean -xdf' or 'make distclean'.
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This option is useful if you have a low bandwidth Internet connection, and by
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setting a path outside the OpenWrt tree downloads will be saved.
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config LOCALMIRROR
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string "Local mirror for source packages" if DEVEL
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default ""
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config AUTOREBUILD
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bool "Automatic rebuild of packages" if DEVEL
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default y
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help
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Automatically rebuild packages when their files change.
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config AUTOREMOVE
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bool "Automatic removal of build directories" if DEVEL
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default n
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help
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Automatically delete build directories after make target completed.
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This allows you to symlink build_dir into a scratch location, e.g. a ramdisk,
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which does not have enough space to keep a complete build_dir.
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config BUILD_SUFFIX
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string "Build suffix to append to the target BUILD_DIR variable" if DEVEL
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default ""
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help
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Build suffix to append to the BUILD_DIR variable, i.e: './build_dir/{target-build-dir}_$(BUILD_SUFFIX)'.
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This allows you to switch to a different .config whilst retaining all the build
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objects generated by the first .config
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config TARGET_ROOTFS_DIR
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string "Override the default TARGET_ROOTFS_DIR variable" if DEVEL
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default ""
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help
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Override the default TARGET_ROOTFS_DIR variable content $(BUILD_DIR) with
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custom path. Use this option to re-define the location of the target
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root filesystem directory.
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config CCACHE
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bool "Use ccache" if DEVEL
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default n
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help
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Compiler cache; see https://ccache.samba.org/
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config CCACHE_DIR
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string "Set ccache directory" if CCACHE
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default ""
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help
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Store ccache in this directory.
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If not set, uses './.ccache'
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config KERNEL_CFLAGS
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string "Kernel extra CFLAGS" if DEVEL
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default "-falign-functions=32" if TARGET_bcm53xx
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default ""
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config EXTERNAL_KERNEL_TREE
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string "Use external kernel tree" if DEVEL
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default ""
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config KERNEL_GIT_CLONE_URI
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string "Enter git repository to clone" if DEVEL
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default ""
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help
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Enter the full git repository path i.e.:
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git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
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This will create a git clone of the kernel in your build directory.
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config KERNEL_GIT_LOCAL_REPOSITORY
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string "Enter path to local reference repository" if DEVEL
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depends on (KERNEL_GIT_CLONE_URI != "")
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default ""
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help
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Enter a full pathname to a local reference git repository.
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In this instance, the --reference option of git clone will
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be used thus creating a quick local clone of your repo.
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config KERNEL_GIT_REF
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string "Enter git ref at which to checkout" if DEVEL
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depends on (KERNEL_GIT_CLONE_URI != "")
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default ""
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help
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Enter the git ref at which to checkout the git repository
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after it is cloned, and before making it a tar-ball.
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It can be a git hash or a branch name.
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If unused, the clone's repository HEAD will be checked-out.
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config KERNEL_GIT_MIRROR_HASH
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string "Enter hash of Git kernel tree source checkout tarball" if DEVEL
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depends on (KERNEL_GIT_CLONE_URI != "")
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default ""
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config BUILD_LOG
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bool "Enable log files during build process" if DEVEL
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help
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If enabled, log files will be written to the ./log directory.
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config BUILD_LOG_DIR
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string "Log folder" if DEVEL
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default ""
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help
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Store build logs in this directory.
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If not set, uses './logs'
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config SRC_TREE_OVERRIDE
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bool "Enable package source tree override" if DEVEL
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help
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If enabled, you can force a package to use a git tree as source
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code instead of the normal tarball. Create a symlink 'git-src'
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in the package directory, pointing to the .git tree that you want
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to pull the source code from.
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config EXTRA_OPTIMIZATION
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string "Additional compiler options" if DEVEL
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default "-fno-caller-saves -fno-plt" if !CONFIG_EXTERNAL_TOOLCHAIN && !arc
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default "-fno-caller-saves"
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help
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Extra target-independent optimizations to use when building for the target.
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