rcu: Put names into TINY_RCU structures under RCU_TRACE

In order to allow event tracing to distinguish between flavors of
RCU, we need those names in the relevant RCU data structures.  TINY_RCU
has avoided them for memory-footprint reasons, so add them only if
CONFIG_RCU_TRACE=y.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

5 files changed, 18 insertions, 27 deletions

diff --git a/kernel/rcu.h b/kernel/rcu.h
index 7bc16436aba0..d7f00ec8b47b 100644
--- a/kernel/rcu.h
+++ b/kernel/rcu.h
@@ -23,6 +23,12 @@
 #ifndef __LINUX_RCU_H
 #define __LINUX_RCU_H
 
+#ifdef CONFIG_RCU_TRACE
+#define RCU_TRACE(stmt) stmt
+#else /* #ifdef CONFIG_RCU_TRACE */
+#define RCU_TRACE(stmt)
+#endif /* #else #ifdef CONFIG_RCU_TRACE */
+
 /*
  * debug_rcu_head_queue()/debug_rcu_head_unqueue() are used internally
  * by call_rcu() and rcu callback execution, and are therefore not part of the
@@ -68,10 +74,10 @@ static inline void __rcu_reclaim(struct rcu_head *head)
         unsigned long offset = (unsigned long)head->func;
 
         if (__is_kfree_rcu_offset(offset)) {
-                trace_rcu_invoke_kfree_callback(head, offset);
+                RCU_TRACE(trace_rcu_invoke_kfree_callback(head, offset));
                 kfree((void *)head - offset);
         } else {
-                trace_rcu_invoke_callback(head);
+                RCU_TRACE(trace_rcu_invoke_callback(head));
                 head->func(head);
         }
 }
diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c
index 19453ba1392e..0d28974b78f4 100644
--- a/kernel/rcutiny.c
+++ b/kernel/rcutiny.c
@@ -38,20 +38,7 @@
 #include <linux/prefetch.h>
 
 #ifdef CONFIG_RCU_TRACE
-
 #include <trace/events/rcu.h>
-
-#else /* #ifdef CONFIG_RCU_TRACE */
-
-/* No by-default tracing in TINY_RCU: Keep TINY_RCU tiny! */
-static void trace_rcu_invoke_kfree_callback(struct rcu_head *rhp,
-                                            unsigned long offset)
-{
-}
-static void trace_rcu_invoke_callback(struct rcu_head *head)
-{
-}
-
 #endif /* #else #ifdef CONFIG_RCU_TRACE */
 
 #include "rcu.h"
diff --git a/kernel/rcutiny_plugin.h b/kernel/rcutiny_plugin.h
index 6b0cedb383e0..791ddf7c99ab 100644
--- a/kernel/rcutiny_plugin.h
+++ b/kernel/rcutiny_plugin.h
@@ -26,29 +26,26 @@
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 
-#ifdef CONFIG_RCU_TRACE
-#define RCU_TRACE(stmt) stmt
-#else /* #ifdef CONFIG_RCU_TRACE */
-#define RCU_TRACE(stmt)
-#endif /* #else #ifdef CONFIG_RCU_TRACE */
-
 /* Global control variables for rcupdate callback mechanism. */
 struct rcu_ctrlblk {
         struct rcu_head *rcucblist;     /* List of pending callbacks (CBs). */
         struct rcu_head **donetail;     /* ->next pointer of last "done" CB. */
         struct rcu_head **curtail;      /* ->next pointer of last CB. */
         RCU_TRACE(long qlen);           /* Number of pending CBs. */
+        RCU_TRACE(char *name);          /* Name of RCU type. */
 };
 
 /* Definition for rcupdate control block. */
 static struct rcu_ctrlblk rcu_sched_ctrlblk = {
         .donetail       = &rcu_sched_ctrlblk.rcucblist,
         .curtail        = &rcu_sched_ctrlblk.rcucblist,
+        RCU_TRACE(.name = "rcu_sched")
 };
 
 static struct rcu_ctrlblk rcu_bh_ctrlblk = {
         .donetail       = &rcu_bh_ctrlblk.rcucblist,
         .curtail        = &rcu_bh_ctrlblk.rcucblist,
+        RCU_TRACE(.name = "rcu_bh")
 };
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
@@ -131,6 +128,7 @@ static struct rcu_preempt_ctrlblk rcu_preempt_ctrlblk = {
         .rcb.curtail = &rcu_preempt_ctrlblk.rcb.rcucblist,
         .nexttail = &rcu_preempt_ctrlblk.rcb.rcucblist,
         .blkd_tasks = LIST_HEAD_INIT(rcu_preempt_ctrlblk.blkd_tasks),
+        RCU_TRACE(.rcb.name = "rcu_preempt")
 };
 
 static int rcu_preempted_readers_exp(void);
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 2a9643bd6ae9..b953e2c72e25 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -61,7 +61,7 @@
 static struct lock_class_key rcu_node_class[NUM_RCU_LVLS];
 
 #define RCU_STATE_INITIALIZER(structname) { \
-        .level = { &structname.node[0] }, \
+        .level = { &structname##_state.node[0] }, \
         .levelcnt = { \
                 NUM_RCU_LVL_0,  /* root of hierarchy. */ \
                 NUM_RCU_LVL_1, \
@@ -72,17 +72,17 @@ static struct lock_class_key rcu_node_class[NUM_RCU_LVLS];
         .signaled = RCU_GP_IDLE, \
         .gpnum = -300, \
         .completed = -300, \
-        .onofflock = __RAW_SPIN_LOCK_UNLOCKED(&structname.onofflock), \
-        .fqslock = __RAW_SPIN_LOCK_UNLOCKED(&structname.fqslock), \
+        .onofflock = __RAW_SPIN_LOCK_UNLOCKED(&structname##_state.onofflock), \
+        .fqslock = __RAW_SPIN_LOCK_UNLOCKED(&structname##_state.fqslock), \
         .n_force_qs = 0, \
         .n_force_qs_ngp = 0, \
         .name = #structname, \
 }
 
-struct rcu_state rcu_sched_state = RCU_STATE_INITIALIZER(rcu_sched_state);
+struct rcu_state rcu_sched_state = RCU_STATE_INITIALIZER(rcu_sched);
 DEFINE_PER_CPU(struct rcu_data, rcu_sched_data);
 
-struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh_state);
+struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh);
 DEFINE_PER_CPU(struct rcu_data, rcu_bh_data);
 
 static struct rcu_state *rcu_state;
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 43daa46bc6f2..a90bf3c17492 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -64,7 +64,7 @@ static void __init rcu_bootup_announce_oddness(void)
 
 #ifdef CONFIG_TREE_PREEMPT_RCU
 
-struct rcu_state rcu_preempt_state = RCU_STATE_INITIALIZER(rcu_preempt_state);
+struct rcu_state rcu_preempt_state = RCU_STATE_INITIALIZER(rcu_preempt);
 DEFINE_PER_CPU(struct rcu_data, rcu_preempt_data);
 static struct rcu_state *rcu_state = &rcu_preempt_state;