rcu_sync: Cleanup the CONFIG_PROVE_RCU checks
1. Rename __rcu_sync_is_idle() to rcu_sync_lockdep_assert() and
change it to use rcu_lockdep_assert().
2. Change rcu_sync_is_idle() to return rsp->gp_state == GP_IDLE
unconditonally, this way we can remove the same check from
rcu_sync_lockdep_assert() and clearly isolate the debugging
code.
Note: rcu_sync_enter()->wait_event(gp_state == GP_PASSED) needs
another CONFIG_PROVE_RCU check, the same as is done in ->sync(); but
this needs some simple preparations in the core RCU code to avoid the
code duplication.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
diff --git a/include/linux/rcu_sync.h b/include/linux/rcu_sync.h
index 8069d64..a63a33e 100644
--- a/include/linux/rcu_sync.h
+++ b/include/linux/rcu_sync.h
@@ -40,7 +40,7 @@
enum rcu_sync_type gp_type;
};
-extern bool __rcu_sync_is_idle(struct rcu_sync *);
+extern void rcu_sync_lockdep_assert(struct rcu_sync *);
/**
* rcu_sync_is_idle() - Are readers permitted to use their fastpaths?
@@ -53,10 +53,9 @@
static inline bool rcu_sync_is_idle(struct rcu_sync *rsp)
{
#ifdef CONFIG_PROVE_RCU
- return __rcu_sync_is_idle(rsp);
-#else
- return !rsp->gp_state; /* GP_IDLE */
+ rcu_sync_lockdep_assert(rsp);
#endif
+ return !rsp->gp_state; /* GP_IDLE */
}
extern void rcu_sync_init(struct rcu_sync *, enum rcu_sync_type);
diff --git a/kernel/rcu/sync.c b/kernel/rcu/sync.c
index 1e353f0..be922c9 100644
--- a/kernel/rcu/sync.c
+++ b/kernel/rcu/sync.c
@@ -63,10 +63,10 @@
#define rss_lock gp_wait.lock
#ifdef CONFIG_PROVE_RCU
-bool __rcu_sync_is_idle(struct rcu_sync *rsp)
+void rcu_sync_lockdep_assert(struct rcu_sync *rsp)
{
- WARN_ON(!gp_ops[rsp->gp_type].held());
- return rsp->gp_state == GP_IDLE;
+ RCU_LOCKDEP_WARN(!gp_ops[rsp->gp_type].held(),
+ "suspicious rcu_sync_is_idle() usage");
}
#endif
