From 7d73c8bac528e3c997dcd070cf87c4383f809c4c Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@nicira.com>
Date: Mon, 21 Jul 2008 13:51:02 -0700
Subject: [PATCH] Don't use atomic_t for tracking table flow counts.
Changes to n_flows is already fully serialized by dp_mutex.
---
datapath/hwtable_dummy/hwtable_dummy.c | 12 +++++-------
datapath/table-hash.c | 14 ++++++--------
datapath/table-linear.c | 17 +++++++----------
3 files changed, 18 insertions(+), 25 deletions(-)
diff --git a/datapath/hwtable_dummy/hwtable_dummy.c b/datapath/hwtable_dummy/hwtable_dummy.c
index 6f7ed8c18..4c6e53727 100644
--- a/datapath/hwtable_dummy/hwtable_dummy.c
+++ b/datapath/hwtable_dummy/hwtable_dummy.c
@@ -63,7 +63,7 @@ struct sw_table_dummy {
struct sw_table swt;
unsigned int max_flows;
- atomic_t n_flows;
+ unsigned int n_flows;
struct list_head flows;
struct list_head iter_flows;
unsigned long int next_serial;
@@ -151,8 +151,7 @@ static int table_dummy_delete(struct sw_table *swt,
&& (!strict || (flow->priority == priority)))
count += do_delete(swt, flow);
}
- if (count)
- atomic_sub(count, &td->n_flows);
+ td->n_flows -= count;
return count;
}
@@ -201,8 +200,7 @@ static int table_dummy_timeout(struct datapath *dp, struct sw_table *swt)
spin_unlock_bh(&pending_free_lock);
mutex_unlock(&dp_mutex);
- if (del_count)
- atomic_sub(del_count, &td->n_flows);
+ td->n_flows -= del_count;
return del_count;
}
@@ -256,7 +254,7 @@ static void table_dummy_stats(struct sw_table *swt,
{
struct sw_table_dummy *td = (struct sw_table_dummy *) swt;
stats->name = "dummy";
- stats->n_flows = atomic_read(&td->n_flows);
+ stats->n_flows = td->n_flows;
stats->max_flows = td->max_flows;
}
@@ -280,7 +278,7 @@ static struct sw_table *table_dummy_create(void)
swt->stats = table_dummy_stats;
td->max_flows = DUMMY_MAX_FLOW;
- atomic_set(&td->n_flows, 0);
+ td->n_flows = 0;
INIT_LIST_HEAD(&td->flows);
INIT_LIST_HEAD(&td->iter_flows);
td->next_serial = 0;
diff --git a/datapath/table-hash.c b/datapath/table-hash.c
index b7475e3b9..202114b68 100644
--- a/datapath/table-hash.c
+++ b/datapath/table-hash.c
@@ -22,7 +22,7 @@ static void kmem_free(void *, size_t);
struct sw_table_hash {
struct sw_table swt;
struct crc32 crc32;
- atomic_t n_flows;
+ unsigned int n_flows;
unsigned int bucket_mask; /* Number of buckets minus 1. */
struct sw_flow **buckets;
};
@@ -53,7 +53,7 @@ static int table_hash_insert(struct sw_table *swt, struct sw_flow *flow)
bucket = find_bucket(swt, &flow->key);
if (*bucket == NULL) {
- atomic_inc(&th->n_flows);
+ th->n_flows++;
rcu_assign_pointer(*bucket, flow);
retval = 1;
} else {
@@ -106,8 +106,7 @@ static int table_hash_delete(struct sw_table *swt,
count += do_delete(bucket, flow);
}
}
- if (count)
- atomic_sub(count, &th->n_flows);
+ th->n_flows -= count;
return count;
}
@@ -127,10 +126,9 @@ static int table_hash_timeout(struct datapath *dp, struct sw_table *swt)
dp_send_flow_expired(dp, flow);
}
}
+ th->n_flows -= count;
mutex_unlock(&dp_mutex);
- if (count)
- atomic_sub(count, &th->n_flows);
return count;
}
@@ -189,7 +187,7 @@ static void table_hash_stats(struct sw_table *swt,
{
struct sw_table_hash *th = (struct sw_table_hash *) swt;
stats->name = "hash";
- stats->n_flows = atomic_read(&th->n_flows);
+ stats->n_flows = th->n_flows;
stats->max_flows = th->bucket_mask + 1;
}
@@ -222,7 +220,7 @@ struct sw_table *table_hash_create(unsigned int polynomial,
swt->stats = table_hash_stats;
crc32_init(&th->crc32, polynomial);
- atomic_set(&th->n_flows, 0);
+ th->n_flows = 0;
return swt;
}
diff --git a/datapath/table-linear.c b/datapath/table-linear.c
index e40929963..e1274bf36 100644
--- a/datapath/table-linear.c
+++ b/datapath/table-linear.c
@@ -16,7 +16,7 @@ struct sw_table_linear {
struct sw_table swt;
unsigned int max_flows;
- atomic_t n_flows;
+ unsigned int n_flows;
struct list_head flows;
struct list_head iter_flows;
unsigned long int next_serial;
@@ -61,10 +61,10 @@ static int table_linear_insert(struct sw_table *swt, struct sw_flow *flow)
}
/* Make sure there's room in the table. */
- if (atomic_read(&tl->n_flows) >= tl->max_flows) {
+ if (tl->n_flows >= tl->max_flows) {
return 0;
}
- atomic_inc(&tl->n_flows);
+ tl->n_flows++;
/* Insert the entry immediately in front of where we're pointing. */
flow->serial = tl->next_serial++;
@@ -96,8 +96,7 @@ static int table_linear_delete(struct sw_table *swt,
&& (!strict || (flow->priority == priority)))
count += do_delete(swt, flow);
}
- if (count)
- atomic_sub(count, &tl->n_flows);
+ tl->n_flows -= count;
return count;
}
@@ -115,10 +114,8 @@ static int table_linear_timeout(struct datapath *dp, struct sw_table *swt)
dp_send_flow_expired(dp, flow);
}
}
+ tl->n_flows -= count;
mutex_unlock(&dp_mutex);
-
- if (count)
- atomic_sub(count, &tl->n_flows);
return count;
}
@@ -163,7 +160,7 @@ static void table_linear_stats(struct sw_table *swt,
{
struct sw_table_linear *tl = (struct sw_table_linear *) swt;
stats->name = "linear";
- stats->n_flows = atomic_read(&tl->n_flows);
+ stats->n_flows = tl->n_flows;
stats->max_flows = tl->max_flows;
}
@@ -187,7 +184,7 @@ struct sw_table *table_linear_create(unsigned int max_flows)
swt->stats = table_linear_stats;
tl->max_flows = max_flows;
- atomic_set(&tl->n_flows, 0);
+ tl->n_flows = 0;
INIT_LIST_HEAD(&tl->flows);
INIT_LIST_HEAD(&tl->iter_flows);
tl->next_serial = 0;
--
2.47.0