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From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com,
	akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca,
	josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de,
	peterz@infradead.org, rostedt@goodmis.org,
	Valdis.Kletnieks@vt.edu, dhowells@redhat.com,
	edumazet@google.com, darren@dvhart.com, fweisbec@gmail.com,
	sbw@mit.edu, "Paul E. McKenney" <paul.mckenney@linaro.org>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH tip/core/rcu 08/12] rcu: Repurpose no-CBs event tracing to future-GP events
Date: Sat, 26 Jan 2013 16:29:59 -0800	[thread overview]
Message-ID: <1359246603-6863-8-git-send-email-paulmck@linux.vnet.ibm.com> (raw)
In-Reply-To: <1359246603-6863-1-git-send-email-paulmck@linux.vnet.ibm.com>

From: "Paul E. McKenney" <paul.mckenney@linaro.org>

Dyntick-idle CPUs need to be able to pre-announce their need for grace
periods.  This can be done using something similar to the mechanism used
by no-CB CPUs to announce their need for grace periods.  This commit
moves in this direction by renaming the no-CBs grace-period event tracing
to suit the new future-grace-period needs.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
 include/trace/events/rcu.h |   16 +++++-----
 kernel/rcutree_plugin.h    |   62 ++++++++++++++++++++++---------------------
 2 files changed, 40 insertions(+), 38 deletions(-)

diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
index cdfed6d..59ebcc8 100644
--- a/include/trace/events/rcu.h
+++ b/include/trace/events/rcu.h
@@ -72,10 +72,10 @@ 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:
+ * Tracepoint for future grace-period events, including those for no-callbacks
+ * CPUs.  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.
@@ -87,7 +87,7 @@ TRACE_EVENT(rcu_grace_period,
  * "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,
+TRACE_EVENT(rcu_future_grace_period,
 
 	TP_PROTO(char *rcuname, unsigned long gpnum, unsigned long completed,
 		 unsigned long c, u8 level, int grplo, int grphi,
@@ -653,9 +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_future_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 d55475b..bcd8268 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -2080,9 +2080,9 @@ 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");
+	trace_rcu_future_grace_period(rsp->name, rnp->gpnum, rnp->completed,
+				      c, rnp->level, rnp->grplo, rnp->grphi,
+				      needmore ? "CleanupMore" : "Cleanup");
 	return needmore;
 }
 
@@ -2229,9 +2229,9 @@ 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");
+	trace_rcu_future_grace_period(rdp->rsp->name, rnp->gpnum,
+				      rnp->completed, c, rnp->level,
+				      rnp->grplo, rnp->grphi, "Startleaf");
 
 	if (rnp->gpnum != rnp->completed) {
 
@@ -2240,10 +2240,10 @@ 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");
+		trace_rcu_future_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 {
@@ -2255,11 +2255,12 @@ 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");
+			trace_rcu_future_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 {
 
@@ -2275,11 +2276,12 @@ 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");
+			trace_rcu_future_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. */
 		}
@@ -2295,9 +2297,9 @@ 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");
+	trace_rcu_future_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],
@@ -2305,14 +2307,14 @@ 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_future_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");
+	trace_rcu_future_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. */
 }
 
-- 
1.7.8


  parent reply	other threads:[~2013-01-27  5:19 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-27  0:29 [PATCH tip/core/rcu 0/14] v2 RCU idle/no-CB changes for 3.9 Paul E. McKenney
2013-01-27  0:29 ` [PATCH tip/core/rcu 01/12] rcu: Remove restrictions on no-CBs CPUs Paul E. McKenney
2013-01-27  0:29   ` [PATCH tip/core/rcu 02/12] rcu: Provide compile-time control for " Paul E. McKenney
2013-01-27  0:29   ` [PATCH tip/core/rcu 03/12] rcu: Distinguish "rcuo" kthreads by RCU flavor Paul E. McKenney
2013-01-27  0:29   ` [PATCH tip/core/rcu 04/12] rcu: Export RCU_FAST_NO_HZ parameters to sysfs Paul E. McKenney
2013-01-27  0:29   ` [PATCH tip/core/rcu 05/12] rcu: Accelerate RCU callbacks at grace-period end Paul E. McKenney
2013-01-27  0:29   ` [PATCH tip/core/rcu 06/12] rcu: Make RCU_FAST_NO_HZ take advantage of numbered callbacks Paul E. McKenney
2013-01-27  0:29   ` [PATCH tip/core/rcu 07/12] rcu: Rearrange locking in rcu_start_gp() Paul E. McKenney
2013-01-27  0:29   ` Paul E. McKenney [this message]
2013-01-27  0:30   ` [PATCH tip/core/rcu 09/12] rcu: Push lock release to rcu_start_gp()'s callers Paul E. McKenney
2013-01-27  0:30   ` [PATCH tip/core/rcu 10/12] rcu: Rename n_nocb_gp_requests to need_future_gp Paul E. McKenney
2013-01-27  0:30   ` [PATCH tip/core/rcu 11/12] rcu: Abstract rcu_start_future_gp() from rcu_nocb_wait_gp() Paul E. McKenney
2013-01-27  0:30   ` [PATCH tip/core/rcu 12/12] rcu: Make rcu_accelerate_cbs() note need for future grace periods Paul E. McKenney

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