[PATCH] rcu: Remove redundant CONFIG_PREEMPT_RCU option

From: Pranith Kumar
Date: Sun Sep 21 2014 - 12:50:04 EST


PREEMPT_RCU and TREE_PREEMPT_RCU serve the same function after TINY_PREEMPT_RCU
has been removed. This patch removes CONFIG_PREEMPT_RCU and uses
CONFIG_TREE_PREEMPT_RCU in its place.

Signed-off-by: Pranith Kumar <bobby.prani@xxxxxxxxx>
---
arch/xtensa/configs/s6105_defconfig | 2 +-
include/linux/init_task.h | 2 +-
include/linux/rcupdate.h | 16 ++++++++--------
include/linux/sched.h | 10 +++++-----
init/Kconfig | 6 ------
kernel/rcu/update.c | 4 ++--
tools/testing/selftests/rcutorture/doc/TINY_RCU.txt | 2 +-
.../selftests/rcutorture/doc/TREE_RCU-kconfig.txt | 2 +-
8 files changed, 19 insertions(+), 25 deletions(-)

diff --git a/arch/xtensa/configs/s6105_defconfig b/arch/xtensa/configs/s6105_defconfig
index 12a492a..dab1a99 100644
--- a/arch/xtensa/configs/s6105_defconfig
+++ b/arch/xtensa/configs/s6105_defconfig
@@ -35,7 +35,7 @@ CONFIG_SYSVIPC_SYSCTL=y
#
# CONFIG_CLASSIC_RCU is not set
# CONFIG_TREE_RCU is not set
-CONFIG_PREEMPT_RCU=y
+CONFIG_TREE_PREEMPT_RCU=y
# CONFIG_RCU_TRACE is not set
# CONFIG_TREE_RCU_TRACE is not set
# CONFIG_PREEMPT_RCU_TRACE is not set
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 77fc43f..39600f4 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -108,7 +108,7 @@ extern struct group_info init_groups;
#else
#define INIT_TASK_RCU_TREE_PREEMPT(tsk)
#endif
-#ifdef CONFIG_PREEMPT_RCU
+#ifdef CONFIG_TREE_PREEMPT_RCU
#define INIT_TASK_RCU_PREEMPT(tsk) \
.rcu_read_lock_nesting = 0, \
.rcu_read_unlock_special.s = 0, \
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index a4a819f..17a15d5 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -103,7 +103,7 @@ void do_trace_rcu_torture_read(const char *rcutorturename,

/* Exported common interfaces */

-#ifdef CONFIG_PREEMPT_RCU
+#ifdef CONFIG_TREE_PREEMPT_RCU

/**
* call_rcu() - Queue an RCU callback for invocation after a grace period.
@@ -140,12 +140,12 @@ void do_trace_rcu_torture_read(const char *rcutorturename,
void call_rcu(struct rcu_head *head,
void (*func)(struct rcu_head *head));

-#else /* #ifdef CONFIG_PREEMPT_RCU */
+#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */

/* In classic RCU, call_rcu() is just call_rcu_sched(). */
#define call_rcu call_rcu_sched

-#endif /* #else #ifdef CONFIG_PREEMPT_RCU */
+#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */

/**
* call_rcu_bh() - Queue an RCU for invocation after a quicker grace period.
@@ -217,7 +217,7 @@ void call_rcu_tasks(struct rcu_head *head, void (*func)(struct rcu_head *head));
void synchronize_rcu_tasks(void);
void rcu_barrier_tasks(void);

-#ifdef CONFIG_PREEMPT_RCU
+#ifdef CONFIG_TREE_PREEMPT_RCU

void __rcu_read_lock(void);
void __rcu_read_unlock(void);
@@ -227,12 +227,12 @@ void synchronize_rcu(void);
/*
* Defined as a macro as it is a very low level header included from
* areas that don't even know about current. This gives the rcu_read_lock()
- * nesting depth, but makes sense only if CONFIG_PREEMPT_RCU -- in other
+ * nesting depth, but makes sense only if CONFIG_TREE_PREEMPT_RCU -- in other
* types of kernel builds, the rcu_read_lock() nesting depth is unknowable.
*/
#define rcu_preempt_depth() (current->rcu_read_lock_nesting)

-#else /* #ifdef CONFIG_PREEMPT_RCU */
+#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */

static inline void __rcu_read_lock(void)
{
@@ -254,7 +254,7 @@ static inline int rcu_preempt_depth(void)
return 0;
}

-#endif /* #else #ifdef CONFIG_PREEMPT_RCU */
+#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */

/* Internal to kernel */
void rcu_init(void);
@@ -530,7 +530,7 @@ static inline int rcu_read_lock_sched_held(void)
} \
} while (0)

-#if defined(CONFIG_PROVE_RCU) && !defined(CONFIG_PREEMPT_RCU)
+#if defined(CONFIG_PROVE_RCU) && !defined(CONFIG_TREE_PREEMPT_RCU)
static inline void rcu_preempt_sleep_check(void)
{
rcu_lockdep_assert(!lock_is_held(&rcu_lock_map),
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 42888d7..6acaa30 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1269,11 +1269,11 @@ struct task_struct {
int nr_cpus_allowed;
cpumask_t cpus_allowed;

-#ifdef CONFIG_PREEMPT_RCU
+#ifdef CONFIG_TREE_PREEMPT_RCU
int rcu_read_lock_nesting;
union rcu_special rcu_read_unlock_special;
struct list_head rcu_node_entry;
-#endif /* #ifdef CONFIG_PREEMPT_RCU */
+#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
#ifdef CONFIG_TREE_PREEMPT_RCU
struct rcu_node *rcu_blocked_node;
#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
@@ -2014,12 +2014,12 @@ extern void task_clear_jobctl_pending(struct task_struct *task,

static inline void rcu_copy_process(struct task_struct *p)
{
-#ifdef CONFIG_PREEMPT_RCU
+#ifdef CONFIG_TREE_PREEMPT_RCU
p->rcu_read_lock_nesting = 0;
p->rcu_read_unlock_special.s = 0;
p->rcu_blocked_node = NULL;
INIT_LIST_HEAD(&p->rcu_node_entry);
-#endif /* #ifdef CONFIG_PREEMPT_RCU */
+#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
#ifdef CONFIG_TASKS_RCU
p->rcu_tasks_holdout = false;
INIT_LIST_HEAD(&p->rcu_tasks_holdout_list);
@@ -2752,7 +2752,7 @@ extern int __cond_resched_softirq(void);

static inline void cond_resched_rcu(void)
{
-#if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
+#if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_TREE_PREEMPT_RCU)
rcu_read_unlock();
cond_resched();
rcu_read_lock();
diff --git a/init/Kconfig b/init/Kconfig
index 8a2b97c..27ad03c 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -501,12 +501,6 @@ config TINY_RCU

endchoice

-config PREEMPT_RCU
- def_bool TREE_PREEMPT_RCU
- help
- This option enables preemptible-RCU code that is common between
- TREE_PREEMPT_RCU and, in the old days, TINY_PREEMPT_RCU.
-
config TASKS_RCU
bool "Task_based RCU implementation using voluntary context switch"
default n
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index 3ef8ba5..8848a32 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -62,7 +62,7 @@ MODULE_ALIAS("rcupdate");

module_param(rcu_expedited, int, 0);

-#ifdef CONFIG_PREEMPT_RCU
+#ifdef CONFIG_TREE_PREEMPT_RCU

/*
* Preemptible RCU implementation for rcu_read_lock().
@@ -108,7 +108,7 @@ void __rcu_read_unlock(void)
}
EXPORT_SYMBOL_GPL(__rcu_read_unlock);

-#endif /* #ifdef CONFIG_PREEMPT_RCU */
+#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */

#ifdef CONFIG_DEBUG_LOCK_ALLOC
static struct lock_class_key rcu_lock_key;
diff --git a/tools/testing/selftests/rcutorture/doc/TINY_RCU.txt b/tools/testing/selftests/rcutorture/doc/TINY_RCU.txt
index 28db67b..4fea92d 100644
--- a/tools/testing/selftests/rcutorture/doc/TINY_RCU.txt
+++ b/tools/testing/selftests/rcutorture/doc/TINY_RCU.txt
@@ -31,7 +31,7 @@ CONFIG_RCU_TORTURE_TEST

CONFIG_HOTPLUG_CPU
CONFIG_PREEMPT
-CONFIG_PREEMPT_RCU
+CONFIG_TREE_PREEMPT_RCU
CONFIG_SMP
CONFIG_TINY_RCU
CONFIG_TREE_PREEMPT_RCU
diff --git a/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt b/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt
index f85c45e..081dece 100644
--- a/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt
+++ b/tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt
@@ -62,7 +62,7 @@ CONFIG_NO_HZ_FULL_SYSIDLE_SMALL
Defer until Frederic uses this.

CONFIG_PREEMPT_COUNT
-CONFIG_PREEMPT_RCU
+CONFIG_TREE_PREEMPT_RCU

Redundant with CONFIG_PREEMPT, ignore.

--
2.1.0

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