Go to file
Linus Torvalds 09bd7c75e5 Kbuild updates for v4.15
One of the most remarkable improvements in this cycle is, Kbuild is
 now able to cache the result of shell commands.  Some variables are
 expensive to compute, for example, $(call cc-option,...) invokes the
 compiler.  It is not efficient to redo this computation every time,
 even when we are not actually building anything.  Kbuild creates a
 hidden file ".cache.mk" that contains invoked shell commands and
 their results.  The speed-up should be noticeable.
 
 Summary:
 
 - Fix arch build issues (hexagon, sh)
 
 - Clean up various Makefiles and scripts
 
 - Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles
 
 - Cache variables that are expensive to compute
 
 - Improve cc-ldopton and ld-option for Clang
 
 - Optimize output directory creation
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJaDxaLAAoJED2LAQed4NsGIHQP/isMxxaIxIAWU56+ZcII74k7
 639VgrKi9n5y25d1dBRTQg+vReHE6E2JbkCqpVOu11t7m0LT7yUK8v3WwyLf1qTN
 GxnqZ/WMQU5/AYVqIWo8jN4FGHpivHJ6qbeiNJM9qN4RAkzG0sZUq746VaFZYmIR
 Lu0Gf4m4qjifkkhXsQdWT5i7yNTidPqaL6GNb+FcFkEHlVre8jma0kJlgfHxru84
 WmETpjQXvHAZ/R61vY6ekAWpqFhw3ecJY96A9npnx+SQVQdSNAdpaU0SK29jB0ON
 /SAfpHg9oa/gD0LFOKV6zkjnAkd4TEjrJEiHHhz5gjT/SbS3T1llBIGZ1oV4X7Y0
 Vlh9KWlm1FJJI4SIzc9qUaQMp6JtLfEfHKJCc45xVaN3fNrDnR8jl80x5+95ELga
 dCkZgnq5u82MtTysCbHBESwDYQaVPyIrh7In+mduglaCqhqj9KoDjoLoiGfCg7SA
 3tPflYVd629w5l5GrazJ40jWn1+ggMtgMOVooJNJ+dINCP+GxsUpH84Ww2Pdic+/
 qLdud6TeqxrZDGzWXqKNLu8alM8NGgSr101l9gIf1oqSyy63duBpMrxGDoIJS3FU
 rFDoFFUhlfkAXNbQHtVGNzKtcpCjURh992j9Fa1+NfMwSce5IHkMwTvPmNSRowi8
 0llLjXhD/bxK6FpdvlV8
 =zIdO
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:
 "One of the most remarkable improvements in this cycle is, Kbuild is
  now able to cache the result of shell commands. Some variables are
  expensive to compute, for example, $(call cc-option,...) invokes the
  compiler. It is not efficient to redo this computation every time,
  even when we are not actually building anything. Kbuild creates a
  hidden file ".cache.mk" that contains invoked shell commands and their
  results. The speed-up should be noticeable.

  Summary:

   - Fix arch build issues (hexagon, sh)

   - Clean up various Makefiles and scripts

   - Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles

   - Cache variables that are expensive to compute

   - Improve cc-ldopton and ld-option for Clang

   - Optimize output directory creation"

* tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits)
  kbuild: move coccicheck help from scripts/Makefile.help to top Makefile
  sh: decompressor: add shipped files to .gitignore
  frv: .gitignore: ignore vmlinux.lds
  selinux: remove unnecessary assignment to subdir-
  kbuild: specify FORCE in Makefile.headersinst as .PHONY target
  kbuild: remove redundant mkdir from ./Kbuild
  kbuild: optimize object directory creation for incremental build
  kbuild: create object directories simpler and faster
  kbuild: filter-out PHONY targets from "targets"
  kbuild: remove redundant $(wildcard ...) for cmd_files calculation
  kbuild: create directory for make cache only when necessary
  sh: select KBUILD_DEFCONFIG depending on ARCH
  kbuild: fix linker feature test macros when cross compiling with Clang
  kbuild: shrink .cache.mk when it exceeds 1000 lines
  kbuild: do not call cc-option before KBUILD_CFLAGS initialization
  kbuild: Cache a few more calls to the compiler
  kbuild: Add a cache for generated variables
  kbuild: add forward declaration of default target to Makefile.asm-generic
  kbuild: remove KBUILD_SUBDIR_ASFLAGS and KBUILD_SUBDIR_CCFLAGS
  hexagon/kbuild: replace CFLAGS_MODULE with KBUILD_CFLAGS_MODULE
  ...
2017-11-17 17:45:29 -08:00
Documentation Merge branch 'akpm' (patches from Andrew) 2017-11-17 16:56:17 -08:00
arch Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
block Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-11-17 12:08:18 -08:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK 2017-11-15 18:21:04 -08:00
drivers Merge branch 'akpm' (patches from Andrew) 2017-11-17 16:56:17 -08:00
firmware License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fs Merge branch 'akpm' (patches from Andrew) 2017-11-17 16:56:17 -08:00
include Merge branch 'akpm' (patches from Andrew) 2017-11-17 16:56:17 -08:00
init EXPERT Kconfig menu: fix broken EXPERT menu 2017-11-17 16:10:05 -08:00
ipc Merge branch 'akpm' (patches from Andrew) 2017-11-17 16:56:17 -08:00
kernel Merge branch 'akpm' (patches from Andrew) 2017-11-17 16:56:17 -08:00
lib Merge branch 'akpm' (patches from Andrew) 2017-11-17 16:56:17 -08:00
mm mm: add infrastructure for get_user_pages_fast() benchmarking 2017-11-17 16:10:04 -08:00
net NFS client updates for Linux 4.15 2017-11-17 14:18:00 -08:00
samples media updates for v4.15-rc1 2017-11-15 20:30:12 -08:00
scripts Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
security Modules updates for v4.15 2017-11-15 13:46:33 -08:00
sound sound updates for 4.15-rc1 2017-11-14 18:01:46 -08:00
tools Merge branch 'akpm' (patches from Andrew) 2017-11-17 16:56:17 -08:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt Merge branch 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-11-17 11:54:55 -08:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore .gitignore: move *.dtb and *.dtb.S patterns to the top-level .gitignore 2017-11-08 11:20:24 -06:00
.mailmap Add Jason Gunthorpe as co-maintainer of the RDMA stack 2017-11-17 09:36:18 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2017-11-17 14:31:27 -08:00
Makefile Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.