[PATCH tip/core/rcu 07/22] softirq: Eliminate unused cond_resched_softirq() macro

From: Paul E. McKenney
Date: Sun Apr 22 2018 - 22:35:42 EST


The cond_resched_softirq() macro is not used anywhere in mainline, so
this commit simplifies the kernel by eliminating it.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
include/linux/sched.h | 8 --------
kernel/sched/core.c | 14 --------------
kernel/softirq.c | 3 +--
3 files changed, 1 insertion(+), 24 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index fe8f7178a22d..9ae6943b7310 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1613,7 +1613,6 @@ static inline int test_tsk_need_resched(struct task_struct *tsk)
* explicit rescheduling in places that are safe. The return
* value indicates whether a reschedule was done in fact.
* cond_resched_lock() will drop the spinlock before scheduling,
- * cond_resched_softirq() will enable bhs before scheduling.
*/
#ifndef CONFIG_PREEMPT
extern int _cond_resched(void);
@@ -1639,13 +1638,6 @@ extern int __cond_resched_lock(spinlock_t *lock);
__cond_resched_lock(lock); \
})

-extern int __cond_resched_softirq(void);
-
-#define cond_resched_softirq() ({ \
- ___might_sleep(__FILE__, __LINE__, SOFTIRQ_DISABLE_OFFSET); \
- __cond_resched_softirq(); \
-})
-
static inline void cond_resched_rcu(void)
{
#if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 5e10aaeebfcc..6a09e6af64b9 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5012,20 +5012,6 @@ int __cond_resched_lock(spinlock_t *lock)
}
EXPORT_SYMBOL(__cond_resched_lock);

-int __sched __cond_resched_softirq(void)
-{
- BUG_ON(!in_softirq());
-
- if (should_resched(SOFTIRQ_DISABLE_OFFSET)) {
- local_bh_enable();
- preempt_schedule_common();
- local_bh_disable();
- return 1;
- }
- return 0;
-}
-EXPORT_SYMBOL(__cond_resched_softirq);
-
/**
* yield - yield the current processor to other threads.
*
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 177de3640c78..03981f1c39ea 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -145,8 +145,7 @@ static void __local_bh_enable(unsigned int cnt)
}

/*
- * Special-case - softirqs can safely be enabled in
- * cond_resched_softirq(), or by __do_softirq(),
+ * Special-case - softirqs can safely be enabled by __do_softirq(),
* without processing still-pending softirqs:
*/
void _local_bh_enable(void)
--
2.5.2