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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-08-06 14:17:29 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-09-20 21:16:21 -0700
commit0d43eb34f9aabcddf41c99b7af2d0ced33e9a3cc (patch)
treeae248d15b7c20f943f0604654980265e7c74bc02 /kernel/rcu
parent97c668b8e983b722e2ed765b98b05f644aff1b13 (diff)
downloadlinux-0d43eb34f9aabcddf41c99b7af2d0ced33e9a3cc.tar.gz
rcu: Invert passed_quiesce and rename to cpu_no_qs
This commit inverts the sense of the rcu_data structure's ->passed_quiesce
field and renames it to ->cpu_no_qs.  This will allow a later commit to
use an "aggregate OR" operation to test expedited as well as normal grace
periods without added overhead.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/tree.c22
-rw-r--r--kernel/rcu/tree.h2
-rw-r--r--kernel/rcu/tree_plugin.h6
-rw-r--r--kernel/rcu/tree_trace.c4
4 files changed, 17 insertions, 17 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 7c158ffc7769..31e7021ced4d 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -245,21 +245,21 @@ static int rcu_gp_in_progress(struct rcu_state *rsp)
  */
 void rcu_sched_qs(void)
 {
-	if (!__this_cpu_read(rcu_sched_data.passed_quiesce)) {
+	if (__this_cpu_read(rcu_sched_data.cpu_no_qs)) {
 		trace_rcu_grace_period(TPS("rcu_sched"),
 				       __this_cpu_read(rcu_sched_data.gpnum),
 				       TPS("cpuqs"));
-		__this_cpu_write(rcu_sched_data.passed_quiesce, 1);
+		__this_cpu_write(rcu_sched_data.cpu_no_qs, false);
 	}
 }
 
 void rcu_bh_qs(void)
 {
-	if (!__this_cpu_read(rcu_bh_data.passed_quiesce)) {
+	if (__this_cpu_read(rcu_bh_data.cpu_no_qs)) {
 		trace_rcu_grace_period(TPS("rcu_bh"),
 				       __this_cpu_read(rcu_bh_data.gpnum),
 				       TPS("cpuqs"));
-		__this_cpu_write(rcu_bh_data.passed_quiesce, 1);
+		__this_cpu_write(rcu_bh_data.cpu_no_qs, false);
 	}
 }
 
@@ -1744,7 +1744,7 @@ static bool __note_gp_changes(struct rcu_state *rsp, struct rcu_node *rnp,
 		 */
 		rdp->gpnum = rnp->gpnum;
 		trace_rcu_grace_period(rsp->name, rdp->gpnum, TPS("cpustart"));
-		rdp->passed_quiesce = 0;
+		rdp->cpu_no_qs = true;
 		rdp->rcu_qs_ctr_snap = __this_cpu_read(rcu_qs_ctr);
 		rdp->core_needs_qs = !!(rnp->qsmask & rdp->grpmask);
 		zero_cpu_stall_ticks(rdp);
@@ -2337,7 +2337,7 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp)
 	rnp = rdp->mynode;
 	raw_spin_lock_irqsave(&rnp->lock, flags);
 	smp_mb__after_unlock_lock();
-	if ((rdp->passed_quiesce == 0 &&
+	if ((rdp->cpu_no_qs &&
 	     rdp->rcu_qs_ctr_snap == __this_cpu_read(rcu_qs_ctr)) ||
 	    rdp->gpnum != rnp->gpnum || rnp->completed == rnp->gpnum ||
 	    rdp->gpwrap) {
@@ -2348,7 +2348,7 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp)
 		 * We will instead need a new quiescent state that lies
 		 * within the current grace period.
 		 */
-		rdp->passed_quiesce = 0;	/* need qs for new gp. */
+		rdp->cpu_no_qs = true;	/* need qs for new gp. */
 		rdp->rcu_qs_ctr_snap = __this_cpu_read(rcu_qs_ctr);
 		raw_spin_unlock_irqrestore(&rnp->lock, flags);
 		return;
@@ -2395,7 +2395,7 @@ rcu_check_quiescent_state(struct rcu_state *rsp, struct rcu_data *rdp)
 	 * Was there a quiescent state since the beginning of the grace
 	 * period? If no, then exit and wait for the next call.
 	 */
-	if (!rdp->passed_quiesce &&
+	if (rdp->cpu_no_qs &&
 	    rdp->rcu_qs_ctr_snap == __this_cpu_read(rcu_qs_ctr))
 		return;
 
@@ -3828,11 +3828,11 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp)
 
 	/* Is the RCU core waiting for a quiescent state from this CPU? */
 	if (rcu_scheduler_fully_active &&
-	    rdp->core_needs_qs && !rdp->passed_quiesce &&
+	    rdp->core_needs_qs && rdp->cpu_no_qs &&
 	    rdp->rcu_qs_ctr_snap == __this_cpu_read(rcu_qs_ctr)) {
 		rdp->n_rp_core_needs_qs++;
 	} else if (rdp->core_needs_qs &&
-		   (rdp->passed_quiesce ||
+		   (!rdp->cpu_no_qs ||
 		    rdp->rcu_qs_ctr_snap != __this_cpu_read(rcu_qs_ctr))) {
 		rdp->n_rp_report_qs++;
 		return 1;
@@ -4155,7 +4155,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
 	rdp->beenonline = true;	 /* We have now been online. */
 	rdp->gpnum = rnp->completed; /* Make CPU later note any new GP. */
 	rdp->completed = rnp->completed;
-	rdp->passed_quiesce = false;
+	rdp->cpu_no_qs = true;
 	rdp->rcu_qs_ctr_snap = per_cpu(rcu_qs_ctr, cpu);
 	rdp->core_needs_qs = false;
 	trace_rcu_grace_period(rsp->name, rdp->gpnum, TPS("cpuonl"));
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 4a0f30676ba8..ded4ceebed76 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -302,7 +302,7 @@ struct rcu_data {
 					/*  is aware of having started. */
 	unsigned long	rcu_qs_ctr_snap;/* Snapshot of rcu_qs_ctr to check */
 					/*  for rcu_all_qs() invocations. */
-	bool		passed_quiesce;	/* User-mode/idle loop etc. */
+	bool		cpu_no_qs;	/* No QS yet for this CPU. */
 	bool		core_needs_qs;	/* Core waits for quiesc state. */
 	bool		beenonline;	/* CPU online at least once. */
 	bool		gpwrap;		/* Possible gpnum/completed wrap. */
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index e33b4f3b8e0a..6977ff0dccb9 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -265,11 +265,11 @@ static void rcu_preempt_ctxt_queue(struct rcu_node *rnp, struct rcu_data *rdp,
  */
 static void rcu_preempt_qs(void)
 {
-	if (!__this_cpu_read(rcu_data_p->passed_quiesce)) {
+	if (__this_cpu_read(rcu_data_p->cpu_no_qs)) {
 		trace_rcu_grace_period(TPS("rcu_preempt"),
 				       __this_cpu_read(rcu_data_p->gpnum),
 				       TPS("cpuqs"));
-		__this_cpu_write(rcu_data_p->passed_quiesce, 1);
+		__this_cpu_write(rcu_data_p->cpu_no_qs, false);
 		barrier(); /* Coordinate with rcu_preempt_check_callbacks(). */
 		current->rcu_read_unlock_special.b.need_qs = false;
 	}
@@ -620,7 +620,7 @@ static void rcu_preempt_check_callbacks(void)
 	}
 	if (t->rcu_read_lock_nesting > 0 &&
 	    __this_cpu_read(rcu_data_p->core_needs_qs) &&
-	    !__this_cpu_read(rcu_data_p->passed_quiesce))
+	    __this_cpu_read(rcu_data_p->cpu_no_qs))
 		t->rcu_read_unlock_special.b.need_qs = true;
 }
 
diff --git a/kernel/rcu/tree_trace.c b/kernel/rcu/tree_trace.c
index 4ac25f8520d6..d373e57109b8 100644
--- a/kernel/rcu/tree_trace.c
+++ b/kernel/rcu/tree_trace.c
@@ -117,11 +117,11 @@ static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
 
 	if (!rdp->beenonline)
 		return;
-	seq_printf(m, "%3d%cc=%ld g=%ld pq=%d/%d qp=%d",
+	seq_printf(m, "%3d%cc=%ld g=%ld cnq=%d/%d:%d",
 		   rdp->cpu,
 		   cpu_is_offline(rdp->cpu) ? '!' : ' ',
 		   ulong2long(rdp->completed), ulong2long(rdp->gpnum),
-		   rdp->passed_quiesce,
+		   rdp->cpu_no_qs,
 		   rdp->rcu_qs_ctr_snap == per_cpu(rcu_qs_ctr, rdp->cpu),
 		   rdp->core_needs_qs);
 	seq_printf(m, " dt=%d/%llx/%d df=%lu",