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locking/percpu-rwsem: Extract __percpu_up_read()

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Move the percpu_up_read() slowpath out of the inline function into a new
__percpu_up_read() to avoid binary size increase from adding a
tracepoint to an inlined function.

Signed-off-by: Dmitry Ilvokhin <d@ilvokhin.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Usama Arif <usama.arif@linux.dev>
Link: https://patch.msgid.link/3dd2a1b9ab4f469e1892766cb63f41d6b0f53d29.1780506267.git.d@ilvokhin.com
This commit is contained in:
Dmitry Ilvokhin 2026-06-04 07:15:06 +00:00 committed by Peter Zijlstra
parent 76080d81e5
commit 7cfa62cf94
2 changed files with 21 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
include/linux/percpu-rwsem.h
View File

@ -107,6 +107,8 @@ static inline bool percpu_down_read_trylock(struct percpu_rw_semaphore *sem)
return ret;
}
extern void __percpu_up_read(struct percpu_rw_semaphore *sem);
static inline void percpu_up_read(struct percpu_rw_semaphore *sem)
{
rwsem_release(&sem->dep_map, _RET_IP_);
@ -118,18 +120,7 @@ static inline void percpu_up_read(struct percpu_rw_semaphore *sem)
if (likely(rcu_sync_is_idle(&sem->rss))) {
this_cpu_dec(*sem->read_count);
} else {
/*
* slowpath; reader will only ever wake a single blocked
* writer.
*/
smp_mb(); /* B matches C */
/*
* In other words, if they see our decrement (presumably to
* aggregate zero, as that is the only time it matters) they
* will also see our critical section.
*/
this_cpu_dec(*sem->read_count);
rcuwait_wake_up(&sem->writer);
__percpu_up_read(sem);
}
preempt_enable();
}

18
kernel/locking/percpu-rwsem.c
View File

@ -288,3 +288,21 @@ void percpu_up_write(struct percpu_rw_semaphore *sem)
rcu_sync_exit(&sem->rss);
}
EXPORT_SYMBOL_GPL(percpu_up_write);
void __percpu_up_read(struct percpu_rw_semaphore *sem)
{
lockdep_assert_preemption_disabled();
/*
* slowpath; reader will only ever wake a single blocked
* writer.
*/
smp_mb(); /* B matches C */
/*
* In other words, if they see our decrement (presumably to
* aggregate zero, as that is the only time it matters) they
* will also see our critical section.
*/
this_cpu_dec(*sem->read_count);
rcuwait_wake_up(&sem->writer);
}
EXPORT_SYMBOL_GPL(__percpu_up_read);