rcu: Simplify RCU_STATE_INITIALIZER() macro (a41bfeb2) · Commits · 戴 / test

The RCU_STATE_INITIALIZER() macro is used only in the rcutree.c file as well as the rcutree_plugin.h file. It is passed as a rvalue to a variable of a similar name. A per_cpu variable is also created with a similar name as well. The uses of RCU_STATE_INITIALIZER() can be simplified to remove some of the duplicate code that is done. Currently the three users of this macro has this format: struct rcu_state rcu_sched_state = RCU_STATE_INITIALIZER(rcu_sched, call_rcu_sched); DEFINE_PER_CPU(struct rcu_data, rcu_sched_data); Notice that "rcu_sched" is called three times. This is the same with the other two users. This can be condensed to just: RCU_STATE_INITIALIZER(rcu_sched, call_rcu_sched); by moving the rest into the macro itself. This also opens the door to allow the RCU tracepoint strings and their addresses to be exported so that userspace tracing tools can translate the contents of the pointers of the RCU tracepoints. The change will allow for helper code to be placed in the RCU_STATE_INITIALIZER() macro to export the name that is used. Signed-off-by:

Steven Rostedt <rostedt@goodmis.org>

kernel/rcutree.c

+6 −8

Original line number	Diff line number	Diff line
		@@ -64,7 +64,8 @@
		static struct lock_class_key rcu_node_class[RCU_NUM_LVLS];
		static struct lock_class_key rcu_fqs_class[RCU_NUM_LVLS];

		#define RCU_STATE_INITIALIZER(sname, sabbr, cr) { \
		#define RCU_STATE_INITIALIZER(sname, sabbr, cr) \
		struct rcu_state sname##_state = { \
		.level = { &sname##_state.node[0] }, \
		.call = cr, \
		.fqs_state = RCU_GP_IDLE, \
		@@ -77,14 +78,11 @@ static struct lock_class_key rcu_fqs_class[RCU_NUM_LVLS];
		.onoff_mutex = __MUTEX_INITIALIZER(sname##_state.onoff_mutex), \
		.name = #sname, \
		.abbr = sabbr, \
		}
		}; \
		DEFINE_PER_CPU(struct rcu_data, sname##_data)

		struct rcu_state rcu_sched_state =
		RCU_STATE_INITIALIZER(rcu_sched, 's', call_rcu_sched);
		DEFINE_PER_CPU(struct rcu_data, rcu_sched_data);

		struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh, 'b', call_rcu_bh);
		DEFINE_PER_CPU(struct rcu_data, rcu_bh_data);
		RCU_STATE_INITIALIZER(rcu_bh, 'b', call_rcu_bh);

		static struct rcu_state *rcu_state;
		LIST_HEAD(rcu_struct_flavors);

kernel/rcutree_plugin.h

+1 −3

Original line number	Diff line number	Diff line
		@@ -110,9 +110,7 @@ static void __init rcu_bootup_announce_oddness(void)

		#ifdef CONFIG_TREE_PREEMPT_RCU

		struct rcu_state rcu_preempt_state =
		RCU_STATE_INITIALIZER(rcu_preempt, 'p', call_rcu);
		DEFINE_PER_CPU(struct rcu_data, rcu_preempt_data);
		static struct rcu_state *rcu_state = &rcu_preempt_state;

		static int rcu_preempted_readers_exp(struct rcu_node *rnp);

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