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Paul E. McKenney 677df9d461 srcu: Fix Kconfig botch when SRCU not selected
If the CONFIG_SRCU option is not selected, for example, when building
arch/tile allnoconfig, the following build errors appear:

	kernel/rcu/tree.o: In function `srcu_online_cpu':
	tree.c:(.text+0x4248): multiple definition of `srcu_online_cpu'
	kernel/rcu/srcutree.o:srcutree.c:(.text+0x2120): first defined here
	kernel/rcu/tree.o: In function `srcu_offline_cpu':
	tree.c:(.text+0x4250): multiple definition of `srcu_offline_cpu'
	kernel/rcu/srcutree.o:srcutree.c:(.text+0x2160): first defined here

The corresponding .config file shows CONFIG_TREE_SRCU=y, but no sign
of CONFIG_SRCU, which fatally confuses SRCU's #ifdefs, resulting in
the above errors.  The reason this occurs is the folowing line in
init/Kconfig's definition for TREE_SRCU:

	default y if !TINY_RCU && !CLASSIC_SRCU

If CONFIG_CLASSIC_SRCU=n, as it will be in for allnoconfig, and if
CONFIG_SMP=y, then we will get CONFIG_TREE_SRCU=y but no CONFIG_SRCU,
as seen in the .config file, and which will result in the above errors.
This error did not show up during rcutorture testing because rcutorture
forces CONFIG_SRCU=y, as it must to prevent build errors in rcutorture.c.

This commit therefore conditions TREE_SRCU (and TINY_SRCU, while it is
at it) with SRCU, like this:

	default y if SRCU && !TINY_RCU && !CLASSIC_SRCU

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20170423162205.GP3956@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-04-24 08:14:48 +02:00
arch Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu 2017-04-23 11:12:44 +02:00
block blk-mq: fix potential oops with polling and blk-mq scheduler 2017-04-20 14:53:28 -06:00
certs certs: Add a secondary system keyring that can be added to dynamically 2016-04-11 22:48:09 +01:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-04-18 09:03:50 -07:00
Documentation Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu 2017-04-23 11:12:44 +02:00
drivers Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu 2017-04-23 11:12:44 +02:00
firmware
fs Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu 2017-04-23 11:12:44 +02:00
include Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu 2017-04-23 11:12:44 +02:00
init srcu: Fix Kconfig botch when SRCU not selected 2017-04-24 08:14:48 +02:00
ipc Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
kernel Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu 2017-04-23 11:12:44 +02:00
lib sparc64: Use LOCKDEP_SMALL, not PROVE_LOCKING_SMALL 2017-04-18 13:11:07 -07:00
mm Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu 2017-04-23 11:12:44 +02:00
net Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu 2017-04-23 11:12:44 +02:00
samples statx: Include a mask for stx_attributes in struct statx 2017-04-03 01:06:00 -04:00
scripts Kbuild fixes for v4.11 2017-04-05 08:37:28 -07:00
security KEYS: fix keyctl_set_reqkey_keyring() to not leak thread keyrings 2017-04-18 15:31:49 +01:00
sound ALSA: hda - fix a problem for lineout on a Dell AIO machine 2017-03-31 10:58:26 +02:00
tools Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu 2017-04-23 11:12:44 +02:00
usr kbuild: initramfs cleanup, set target from Kconfig 2017-01-05 09:40:16 -08:00
virt KVM/ARM Fixes for v4.11-rc6 2017-04-05 16:27:47 +02:00
.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 Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-08-02 16:48:52 -04:00
.mailmap mailmap: add Martin Kepplinger's email 2017-04-13 18:24:21 -07:00
COPYING
CREDITS MAINTAINERS: Remove old e-mail address 2017-02-13 12:24:56 -05:00
Kbuild scripts/gdb: provide linux constants 2016-05-23 17:04:14 -07:00
Kconfig
MAINTAINERS bpf, doc: update bpf maintainers entry 2017-04-21 15:25:10 -04:00
Makefile Linux 4.11-rc7 2017-04-16 13:00:18 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

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.