[ltt-dev] [PATCH 07/10] call_rcu: remove write-only qlen variable

[Paolo Bonzini]

The qlen variable is write-only, we can remove it easily.

Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
---
 urcu-call-rcu-impl.h |    9 ---------
 1 files changed, 0 insertions(+), 9 deletions(-)

diff --git a/urcu-call-rcu-impl.h b/urcu-call-rcu-impl.h
index 7e6acdd..ca597d0 100644
--- a/urcu-call-rcu-impl.h
+++ b/urcu-call-rcu-impl.h
@@ -47,7 +47,6 @@ struct call_rcu_data {
 	struct cds_wfq_queue cbs;
 	unsigned long flags;
 	int futex;
-	unsigned long qlen;
 	pthread_t tid;
 	int cpu_affinity;
 	struct cds_list_head list;
@@ -198,7 +197,6 @@ int set_thread_cpu_affinity(struct call_rcu_data *crdp)
 
 static void *call_rcu_thread(void *arg)
 {
-	unsigned long cbcount;
 	struct cds_wfq_node *cbs;
 	struct cds_wfq_node **cbs_tail;
 	struct call_rcu_data *crdp = (struct call_rcu_data *)arg;
@@ -218,7 +216,6 @@ static void *call_rcu_thread(void *arg)
 			cbs_tail = (struct cds_wfq_node **)
 				uatomic_xchg(&crdp->cbs.tail, &crdp->cbs.head);
 			synchronize_rcu();
-			cbcount = 0;
 			do {
 				while (cbs->next == NULL &&
 				       &cbs->next != cbs_tail)
@@ -230,9 +227,7 @@ static void *call_rcu_thread(void *arg)
 				rhp = (struct rcu_head *)cbs;
 				cbs = cbs->next;
 				rhp->func(rhp);
-				cbcount++;
 			} while (cbs != NULL);
-			uatomic_sub(&crdp->qlen, cbcount);
 		}
 		if (uatomic_read(&crdp->flags) & URCU_CALL_RCU_STOP)
 			break;
@@ -267,7 +262,6 @@ static void call_rcu_data_init(struct call_rcu_data **crdpp,
 	}
 	memset(crdp, '\0', sizeof(*crdp));
 	cds_wfq_init(&crdp->cbs);
-	crdp->qlen = 0;
 	crdp->futex = 0;
 	crdp->flags = flags;
 	cds_list_add(&crdp->list, &call_rcu_data_list);
@@ -519,7 +513,6 @@ void call_rcu(struct rcu_head *head,
 	head->func = func;
 	crdp = get_call_rcu_data();
 	cds_wfq_enqueue(&crdp->cbs, &head->next);
-	uatomic_inc(&crdp->qlen);
 	wake_call_rcu_thread(crdp);
 }
 
@@ -565,8 +558,6 @@ void call_rcu_data_free(struct call_rcu_data *crdp)
 		cbs_endprev = (struct cds_wfq_node **)
 			uatomic_xchg(&default_call_rcu_data, cbs_tail);
 		*cbs_endprev = cbs;
-		uatomic_add(&default_call_rcu_data->qlen,
-			    uatomic_read(&crdp->qlen));
 		cds_list_del(&crdp->list);
 		free(crdp);
 	}
-- 
1.7.4.4