Commit a2e05ddd authored by Zhouyi Zhou's avatar Zhouyi Zhou Committed by Peter Zijlstra
Browse files

lockdep: Improve comments in wait-type checks 



Comments in wait-type checks be improved by mentioning the
PREEPT_RT kernel configure option.

Signed-off-by: default avatarZhouyi Zhou <zhouzhouyi@gmail.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Link: https://lkml.kernel.org/r/20210811025920.20751-1-zhouzhouyi@gmail.com
parent 2507003a

include/linux/lockdep_types.h

+1 −1
Original line number Diff line number Diff line
@@ -21,7 +21,7 @@ enum lockdep_wait_type { 
	LD_WAIT_SPIN,		/* spin loops, raw_spinlock_t etc.. */



#ifdef CONFIG_PROVE_RAW_LOCK_NESTING

	LD_WAIT_CONFIG,		/* CONFIG_PREEMPT_LOCK, spinlock_t etc.. */

	LD_WAIT_CONFIG,		/* preemptible in PREEMPT_RT, spinlock_t etc.. */

#else

	LD_WAIT_CONFIG = LD_WAIT_SPIN,

#endif

kernel/locking/lockdep.c

+1 −1
Original line number Diff line number Diff line
@@ -4671,7 +4671,7 @@ print_lock_invalid_wait_context(struct task_struct *curr, 
/*

 * Verify the wait_type context.

 *

 * This check validates we takes locks in the right wait-type order; that is it

 * This check validates we take locks in the right wait-type order; that is it

 * ensures that we do not take mutexes inside spinlocks and do not attempt to

 * acquire spinlocks inside raw_spinlocks and the sort.

 *

kernel/rcu/update.c

+2 −2
Original line number Diff line number Diff line
@@ -247,7 +247,7 @@ struct lockdep_map rcu_lock_map = { 
	.name = "rcu_read_lock",

	.key = &rcu_lock_key,

	.wait_type_outer = LD_WAIT_FREE,

	.wait_type_inner = LD_WAIT_CONFIG, /* XXX PREEMPT_RCU ? */

	.wait_type_inner = LD_WAIT_CONFIG, /* PREEMPT_RT implies PREEMPT_RCU */

};

EXPORT_SYMBOL_GPL(rcu_lock_map);
@@ -256,7 +256,7 @@ struct lockdep_map rcu_bh_lock_map = { 
	.name = "rcu_read_lock_bh",

	.key = &rcu_bh_lock_key,

	.wait_type_outer = LD_WAIT_FREE,

	.wait_type_inner = LD_WAIT_CONFIG, /* PREEMPT_LOCK also makes BH preemptible */

	.wait_type_inner = LD_WAIT_CONFIG, /* PREEMPT_RT makes BH preemptible. */

};

EXPORT_SYMBOL_GPL(rcu_bh_lock_map);