Commit f995443f authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Ingo Molnar
Browse files

locking/seqlock: Simplify SEQCOUNT_LOCKNAME() 



1. Kill the "lockmember" argument. It is always s->lock plus
   __seqprop_##lockname##_sequence() already uses s->lock and
   ignores "lockmember".

2. Kill the "lock_acquire" argument. __seqprop_##lockname##_sequence()
   can use the same "lockbase" prefix for _lock and _unlock.

Apart from line numbers, gcc -E outputs the same code.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20231012143158.GA16133@redhat.com
parent 4fbf8b13

include/linux/seqlock.h

+8 −10
Original line number Diff line number Diff line
@@ -191,11 +191,9 @@ static inline void seqcount_lockdep_reader_access(const seqcount_t *s) 
 * @lockname:		"LOCKNAME" part of seqcount_LOCKNAME_t

 * @locktype:		LOCKNAME canonical C data type

 * @preemptible:	preemptibility of above locktype

 * @lockmember:		argument for lockdep_assert_held()

 * @lockbase:		associated lock release function (prefix only)

 * @lock_acquire:	associated lock acquisition function (full call)

 * @lockbase:		prefix for associated lock/unlock

 */

#define SEQCOUNT_LOCKNAME(lockname, locktype, preemptible, lockmember, lockbase, lock_acquire) \

#define SEQCOUNT_LOCKNAME(lockname, locktype, preemptible, lockbase)	\

typedef struct seqcount_##lockname {					\

	seqcount_t		seqcount;				\

	__SEQ_LOCK(locktype	*lock);					\
@@ -216,7 +214,7 @@ __seqprop_##lockname##_sequence(const seqcount_##lockname##_t *s) \ 
		return seq;						\

									\

	if (preemptible && unlikely(seq & 1)) {				\

		__SEQ_LOCK(lock_acquire);				\

		__SEQ_LOCK(lockbase##_lock(s->lock));			\

		__SEQ_LOCK(lockbase##_unlock(s->lock));			\

									\

		/*							\
@@ -242,7 +240,7 @@ __seqprop_##lockname##_preemptible(const seqcount_##lockname##_t *s) \ 
static __always_inline void						\

__seqprop_##lockname##_assert(const seqcount_##lockname##_t *s)		\

{									\

	__SEQ_LOCK(lockdep_assert_held(lockmember));			\

	__SEQ_LOCK(lockdep_assert_held(s->lock));			\

}



/*
@@ -271,10 +269,10 @@ static inline void __seqprop_assert(const seqcount_t *s) 


#define __SEQ_RT	IS_ENABLED(CONFIG_PREEMPT_RT)



SEQCOUNT_LOCKNAME(raw_spinlock, raw_spinlock_t,  false,    s->lock,        raw_spin, raw_spin_lock(s->lock))

SEQCOUNT_LOCKNAME(spinlock,     spinlock_t,      __SEQ_RT, s->lock,        spin,     spin_lock(s->lock))

SEQCOUNT_LOCKNAME(rwlock,       rwlock_t,        __SEQ_RT, s->lock,        read,     read_lock(s->lock))

SEQCOUNT_LOCKNAME(mutex,        struct mutex,    true,     s->lock,        mutex,    mutex_lock(s->lock))

SEQCOUNT_LOCKNAME(raw_spinlock, raw_spinlock_t,  false,    raw_spin)

SEQCOUNT_LOCKNAME(spinlock,     spinlock_t,      __SEQ_RT, spin)

SEQCOUNT_LOCKNAME(rwlock,       rwlock_t,        __SEQ_RT, read)

SEQCOUNT_LOCKNAME(mutex,        struct mutex,    true,     mutex)



/*

 * SEQCNT_LOCKNAME_ZERO - static initializer for seqcount_LOCKNAME_t