rcu_sync: Simplify rcu_sync using new rcu_sync_ops structure
This commit adds the new struct rcu_sync_ops which holds sync/call
methods, and turns the function pointers in rcu_sync_struct into an array
of struct rcu_sync_ops. This simplifies the "init" helpers by collapsing
a switch statement and explicit multiple definitions into a simple
assignment and a helper macro, respectively.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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 cb044df..c6d2272 100644
--- a/include/linux/rcu_sync.h
+++ b/include/linux/rcu_sync.h
@@ -26,6 +26,8 @@
#include <linux/wait.h>
#include <linux/rcupdate.h>
+enum rcu_sync_type { RCU_SYNC, RCU_SCHED_SYNC, RCU_BH_SYNC };
+
/* Structure to mediate between updaters and fastpath-using readers. */
struct rcu_sync {
int gp_state;
@@ -35,43 +37,9 @@
int cb_state;
struct rcu_head cb_head;
- void (*sync)(void);
- void (*call)(struct rcu_head *, void (*)(struct rcu_head *));
+ enum rcu_sync_type gp_type;
};
-#define ___RCU_SYNC_INIT(name) \
- .gp_state = 0, \
- .gp_count = 0, \
- .gp_wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.gp_wait), \
- .cb_state = 0
-
-#define __RCU_SCHED_SYNC_INIT(name) { \
- ___RCU_SYNC_INIT(name), \
- .sync = synchronize_sched, \
- .call = call_rcu_sched, \
-}
-
-#define __RCU_BH_SYNC_INIT(name) { \
- ___RCU_SYNC_INIT(name), \
- .sync = synchronize_rcu_bh, \
- .call = call_rcu_bh, \
-}
-
-#define __RCU_SYNC_INIT(name) { \
- ___RCU_SYNC_INIT(name), \
- .sync = synchronize_rcu, \
- .call = call_rcu, \
-}
-
-#define DEFINE_RCU_SCHED_SYNC(name) \
- struct rcu_sync name = __RCU_SCHED_SYNC_INIT(name)
-
-#define DEFINE_RCU_BH_SYNC(name) \
- struct rcu_sync name = __RCU_BH_SYNC_INIT(name)
-
-#define DEFINE_RCU_SYNC(name) \
- struct rcu_sync name = __RCU_SYNC_INIT(name)
-
/**
* rcu_sync_is_idle() - Are readers permitted to use their fastpaths?
* @rsp: Pointer to rcu_sync structure to use for synchronization
@@ -85,10 +53,28 @@
return !rsp->gp_state; /* GP_IDLE */
}
-enum rcu_sync_type { RCU_SYNC, RCU_SCHED_SYNC, RCU_BH_SYNC };
-
extern void rcu_sync_init(struct rcu_sync *, enum rcu_sync_type);
extern void rcu_sync_enter(struct rcu_sync *);
extern void rcu_sync_exit(struct rcu_sync *);
+#define __RCU_SYNC_INITIALIZER(name, type) { \
+ .gp_state = 0, \
+ .gp_count = 0, \
+ .gp_wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.gp_wait), \
+ .cb_state = 0, \
+ .gp_type = type, \
+ }
+
+#define __DEFINE_RCU_SYNC(name, type) \
+ struct rcu_sync_struct name = __RCU_SYNC_INITIALIZER(name, type)
+
+#define DEFINE_RCU_SYNC(name) \
+ __DEFINE_RCU_SYNC(name, RCU_SYNC)
+
+#define DEFINE_RCU_SCHED_SYNC(name) \
+ __DEFINE_RCU_SYNC(name, RCU_SCHED_SYNC)
+
+#define DEFINE_RCU_BH_SYNC(name) \
+ __DEFINE_RCU_SYNC(name, RCU_BH_SYNC)
+
#endif /* _LINUX_RCU_SYNC_H_ */