kernel-ark/Documentation/RCU
Zhouyi Zhou 3ac8587852 rcu: Fix undefined Kconfig macros
Invoking scripts/checkkconfigsymbols.py in the Linux-kernel source tree
located the following issues:

1. TREE_PREEMPT_RCU
Referencing files: arch/sh/configs/sdk7786_defconfig

It should now be CONFIG_PREEMPT_RCU. Except that the CONFIG_PREEMPT=y in
that same file implies CONFIG_PREEMPT_RCU=y.  Therefore, delete the
CONFIG_TREE_PREEMPT_RCU=y line.

The reason is as follows:

In kernel/rcu/Kconfig, we have
config PREEMPT_RCU
        bool
        default y if PREEMPTION

https://www.kernel.org/doc/Documentation/kbuild/kconfig-language.txt says,
"The default value is only assigned to the config symbol if no other value
 was set by the user (via the input prompt above)."
there is no prompt in config PREEMPT_RCU entry, so we are guaranteed to
get CONFIG_PREEMPT_RCU=y when CONFIG_PREEMPT is present.

2. RCU_CPU_STALL_INFO
Referencing files: arch/xtensa/configs/nommu_kc705_defconfig

The old Kconfig option RCU_CPU_STALL_INFO was removed by commit
75c27f119b ("rcu: Remove CONFIG_RCU_CPU_STALL_INFO"), and the kernel
now acts as if this Kconfig option was unconditionally enabled.

3. RCU_NOCB_CPU_ALL
Referencing files:
Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst

This is an old snapshot of the code. I update this from the real
rcu_prepare_for_idle() function in kernel/rcu/tree_plugin.h.
This change was tested by invoking "make htmldocs".

4. RCU_TORTURE_TESTS
Referencing files: kernel/rcu/rcutorture.c

Forward-progress checking conflicts with CPU-stall testing, so we should
complain at "modprobe rcutorture" when both are enabled.

Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-09-13 16:32:46 -07:00
..
Design rcu: Fix undefined Kconfig macros 2021-09-13 16:32:46 -07:00
arrayRCU.rst doc: Convert arrayRCU.txt to arrayRCU.rst 2019-12-10 18:51:19 -08:00
checklist.rst Documentation/RCU: Fix emphasis markers 2021-07-20 13:36:33 -07:00
index.rst docs: RCU: Convert stallwarn.txt to ReST 2020-06-29 11:58:11 -07:00
listRCU.rst doc/RCU/listRCU: Update example function name 2020-02-27 07:03:13 -08:00
lockdep-splat.rst docs: RCU: Convert lockdep-splat.txt to ReST 2020-06-29 11:58:10 -07:00
lockdep.rst docs: Fix function name trailing double-()s 2020-08-24 17:19:07 -06:00
NMI-RCU.rst drivers: Remove CONFIG_OPROFILE support 2021-01-29 10:06:24 +05:30
rcu_dereference.rst Documentation/RCU: Fix emphasis markers 2021-07-20 13:36:33 -07:00
rcu.rst doc/RCU/rcu: Use https instead of http if possible 2020-02-27 07:03:13 -08:00
rcubarrier.rst doc: Use CONFIG_PREEMPTION 2021-01-06 16:10:44 -08:00
rculist_nulls.rst docs: RCU: Don't duplicate chapter names in rculist_nulls.rst 2020-06-29 11:58:11 -07:00
rcuref.rst docs: RCU: Convert rcuref.txt to ReST 2020-06-29 11:58:11 -07:00
RTFP.txt docs: Correctly spell Stephen Hemminger's name 2021-03-15 13:53:24 -07:00
stallwarn.rst doc: Add another stall-warning root cause in stallwarn.rst 2021-09-13 16:32:46 -07:00
torture.rst docs: RCU: Convert torture.txt to ReST 2020-06-29 11:58:11 -07:00
UP.rst doc: RCU callback locks need only _bh, not necessarily _irq 2019-06-28 09:10:40 -06:00
whatisRCU.rst doc: Use CONFIG_PREEMPTION 2021-01-06 16:10:44 -08:00