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authorPaul E. McKenney <paul.mckenney@linaro.org>2013-02-08 23:55:02 (GMT)
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2013-03-26 15:04:46 (GMT)
commit09c7b890622d72b5e004cc249bbe610e8b928ddf (patch)
tree4326a3d6baaebaeb3417f0593bb017c2477b973b
parent21e7a6087480451804124cee27c0a7d0a7de1564 (diff)
downloadlinux-09c7b890622d72b5e004cc249bbe610e8b928ddf.tar.xz
rcu: Add event tracing for no-CBs CPUs' grace periods
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
-rw-r--r--include/trace/events/rcu.h55
-rw-r--r--kernel/rcutree_plugin.h30
2 files changed, 85 insertions, 0 deletions
diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
index 1918e83..cdfed6d 100644
--- a/include/trace/events/rcu.h
+++ b/include/trace/events/rcu.h
@@ -72,6 +72,58 @@ TRACE_EVENT(rcu_grace_period,
);
/*
+ * Tracepoint for no-callbacks grace-period events. The caller should
+ * pull the data from the rcu_node structure, other than rcuname, which
+ * comes from the rcu_state structure, and event, which is one of the
+ * following:
+ *
+ * "Startleaf": Request a nocb grace period based on leaf-node data.
+ * "Startedleaf": Leaf-node start proved sufficient.
+ * "Startedleafroot": Leaf-node start proved sufficient after checking root.
+ * "Startedroot": Requested a nocb grace period based on root-node data.
+ * "StartWait": Start waiting for the requested grace period.
+ * "ResumeWait": Resume waiting after signal.
+ * "EndWait": Complete wait.
+ * "Cleanup": Clean up rcu_node structure after previous GP.
+ * "CleanupMore": Clean up, and another no-CB GP is needed.
+ */
+TRACE_EVENT(rcu_nocb_grace_period,
+
+ TP_PROTO(char *rcuname, unsigned long gpnum, unsigned long completed,
+ unsigned long c, u8 level, int grplo, int grphi,
+ char *gpevent),
+
+ TP_ARGS(rcuname, gpnum, completed, c, level, grplo, grphi, gpevent),
+
+ TP_STRUCT__entry(
+ __field(char *, rcuname)
+ __field(unsigned long, gpnum)
+ __field(unsigned long, completed)
+ __field(unsigned long, c)
+ __field(u8, level)
+ __field(int, grplo)
+ __field(int, grphi)
+ __field(char *, gpevent)
+ ),
+
+ TP_fast_assign(
+ __entry->rcuname = rcuname;
+ __entry->gpnum = gpnum;
+ __entry->completed = completed;
+ __entry->c = c;
+ __entry->level = level;
+ __entry->grplo = grplo;
+ __entry->grphi = grphi;
+ __entry->gpevent = gpevent;
+ ),
+
+ TP_printk("%s %lu %lu %lu %u %d %d %s",
+ __entry->rcuname, __entry->gpnum, __entry->completed,
+ __entry->c, __entry->level, __entry->grplo, __entry->grphi,
+ __entry->gpevent)
+);
+
+/*
* Tracepoint for grace-period-initialization events. These are
* distinguished by the type of RCU, the new grace-period number, the
* rcu_node structure level, the starting and ending CPU covered by the
@@ -601,6 +653,9 @@ TRACE_EVENT(rcu_barrier,
#define trace_rcu_grace_period(rcuname, gpnum, gpevent) do { } while (0)
#define trace_rcu_grace_period_init(rcuname, gpnum, level, grplo, grphi, \
qsmask) do { } while (0)
+#define trace_rcu_nocb_grace_period(rcuname, gpnum, completed, c, \
+ level, grplo, grphi, event) \
+ do { } while (0)
#define trace_rcu_preempt_task(rcuname, pid, gpnum) do { } while (0)
#define trace_rcu_unlock_preempted_task(rcuname, gpnum, pid) do { } while (0)
#define trace_rcu_quiescent_state_report(rcuname, gpnum, mask, qsmask, level, \
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 7225a5a..e32236e 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -2201,6 +2201,9 @@ static int rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp)
wake_up_all(&rnp->nocb_gp_wq[c & 0x1]);
rnp->n_nocb_gp_requests[c & 0x1] = 0;
needmore = rnp->n_nocb_gp_requests[(c + 1) & 0x1];
+ trace_rcu_nocb_grace_period(rsp->name, rnp->gpnum, rnp->completed,
+ c, rnp->level, rnp->grplo, rnp->grphi,
+ needmore ? "CleanupMore" : "Cleanup");
return needmore;
}
@@ -2347,6 +2350,9 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
/* Count our request for a grace period. */
rnp->n_nocb_gp_requests[c & 0x1]++;
+ trace_rcu_nocb_grace_period(rdp->rsp->name, rnp->gpnum, rnp->completed,
+ c, rnp->level, rnp->grplo, rnp->grphi,
+ "Startleaf");
if (rnp->gpnum != rnp->completed) {
@@ -2355,6 +2361,10 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
* is in progress, so we are done. When this grace
* period ends, our request will be acted upon.
*/
+ trace_rcu_nocb_grace_period(rdp->rsp->name,
+ rnp->gpnum, rnp->completed, c,
+ rnp->level, rnp->grplo, rnp->grphi,
+ "Startedleaf");
raw_spin_unlock_irqrestore(&rnp->lock, flags);
} else {
@@ -2366,6 +2376,11 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
if (rnp != rnp_root)
raw_spin_lock(&rnp_root->lock); /* irqs disabled. */
if (rnp_root->gpnum != rnp_root->completed) {
+ trace_rcu_nocb_grace_period(rdp->rsp->name,
+ rnp->gpnum, rnp->completed,
+ c, rnp->level,
+ rnp->grplo, rnp->grphi,
+ "Startedleafroot");
raw_spin_unlock(&rnp_root->lock); /* irqs disabled. */
} else {
@@ -2381,6 +2396,11 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
c = rnp_root->completed + 1;
rnp->n_nocb_gp_requests[c & 0x1]++;
rnp_root->n_nocb_gp_requests[c & 0x1]++;
+ trace_rcu_nocb_grace_period(rdp->rsp->name,
+ rnp->gpnum, rnp->completed,
+ c, rnp->level,
+ rnp->grplo, rnp->grphi,
+ "Startedroot");
local_save_flags(flags1);
rcu_start_gp(rdp->rsp, flags1); /* Rlses ->lock. */
}
@@ -2396,6 +2416,9 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
* Wait for the grace period. Do so interruptibly to avoid messing
* up the load average.
*/
+ trace_rcu_nocb_grace_period(rdp->rsp->name, rnp->gpnum, rnp->completed,
+ c, rnp->level, rnp->grplo, rnp->grphi,
+ "StartWait");
for (;;) {
wait_event_interruptible(
rnp->nocb_gp_wq[c & 0x1],
@@ -2403,7 +2426,14 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
if (likely(d))
break;
flush_signals(current);
+ trace_rcu_nocb_grace_period(rdp->rsp->name,
+ rnp->gpnum, rnp->completed, c,
+ rnp->level, rnp->grplo, rnp->grphi,
+ "ResumeWait");
}
+ trace_rcu_nocb_grace_period(rdp->rsp->name, rnp->gpnum, rnp->completed,
+ c, rnp->level, rnp->grplo, rnp->grphi,
+ "EndWait");
smp_mb(); /* Ensure that CB invocation happens after GP end. */
}