[PATCH v3 14/17] net,rds: use new hashtable implementation

Sasha Levin
2012-08-22T02:28:32Z

Switch rds to use the new hashtable implementation. This reduces the amount of
generic unrelated code in rds.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
---
net/rds/bind.c | 28 +++++++++-----
net/rds/connection.c | 102 ++++++++++++++++++++++----------------------------
2 files changed, 63 insertions(+), 67 deletions(-)

diff --git a/net/rds/bind.c b/net/rds/bind.c
index 637bde5..79d65ce 100644
--- a/net/rds/bind.c
+++ b/net/rds/bind.c
@@ -36,16 +36,16 @@
#include <linux/if_arp.h>
#include <linux/jhash.h>
#include <linux/ratelimit.h>
+#include <linux/hashtable.h>
#include "rds.h"

-#define BIND_HASH_SIZE 1024
-static struct hlist_head bind_hash_table[BIND_HASH_SIZE];
+#define BIND_HASH_BITS 10
+static DEFINE_HASHTABLE(bind_hash_table, BIND_HASH_BITS);
static DEFINE_SPINLOCK(rds_bind_lock);

-static struct hlist_head *hash_to_bucket(__be32 addr, __be16 port)
+static u32 rds_hash(__be32 addr, __be16 port)
{
- return bind_hash_table + (jhash_2words((u32)addr, (u32)port, 0) &
- (BIND_HASH_SIZE - 1));
+ return jhash_2words((u32)addr, (u32)port, 0);
}

static struct rds_sock *rds_bind_lookup(__be32 addr, __be16 port,
@@ -53,12 +53,12 @@ static struct rds_sock *rds_bind_lookup(__be32 addr, __be16 port,
{
struct rds_sock *rs;
struct hlist_node *node;
- struct hlist_head *head = hash_to_bucket(addr, port);
+ u32 key = rds_hash(addr, port);
u64 cmp;
u64 needle = ((u64)be32_to_cpu(addr) << 32) | be16_to_cpu(port);

rcu_read_lock();
- hlist_for_each_entry_rcu(rs, node, head, rs_bound_node) {
+ hash_for_each_possible_rcu(bind_hash_table, rs, node, rs_bound_node, key) {
cmp = ((u64)be32_to_cpu(rs->rs_bound_addr) << 32) |
be16_to_cpu(rs->rs_bound_port);

@@ -74,13 +74,13 @@ static struct rds_sock *rds_bind_lookup(__be32 addr, __be16 port,
* make sure our addr and port are set before
* we are added to the list, other people
* in rcu will find us as soon as the
- * hlist_add_head_rcu is done
+ * hash_add_rcu is done
*/
insert->rs_bound_addr = addr;
insert->rs_bound_port = port;
rds_sock_addref(insert);

- hlist_add_head_rcu(&insert->rs_bound_node, head);
+ hash_add_rcu(bind_hash_table, &insert->rs_bound_node, key);
}
return NULL;
}
@@ -152,7 +152,7 @@ void rds_remove_bound(struct rds_sock *rs)
rs, &rs->rs_bound_addr,
ntohs(rs->rs_bound_port));

- hlist_del_init_rcu(&rs->rs_bound_node);
+ hash_del_rcu(&rs->rs_bound_node);
rds_sock_put(rs);
rs->rs_bound_addr = 0;
}
@@ -202,3 +202,11 @@ out:
synchronize_rcu();
return ret;
}
+
+static int __init rds_init(void)
+{
+ hash_init(bind_hash_table);
+ return 0;
+}
+
+module_init(rds_init);
diff --git a/net/rds/connection.c b/net/rds/connection.c
index 9e07c75..5b09ee1 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -34,28 +34,24 @@
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/export.h>
+#include <linux/hashtable.h>
#include <net/inet_hashtables.h>

#include "rds.h"
#include "loop.h"

#define RDS_CONNECTION_HASH_BITS 12
-#define RDS_CONNECTION_HASH_ENTRIES (1 << RDS_CONNECTION_HASH_BITS)
-#define RDS_CONNECTION_HASH_MASK (RDS_CONNECTION_HASH_ENTRIES - 1)

/* converting this to RCU is a chore for another day.. */
static DEFINE_SPINLOCK(rds_conn_lock);
static unsigned long rds_conn_count;
-static struct hlist_head rds_conn_hash[RDS_CONNECTION_HASH_ENTRIES];
+static DEFINE_HASHTABLE(rds_conn_hash, RDS_CONNECTION_HASH_BITS);
static struct kmem_cache *rds_conn_slab;

-static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr)
+static unsigned long rds_conn_hashfn(__be32 laddr, __be32 faddr)
{
/* Pass NULL, don't need struct net for hash */
- unsigned long hash = inet_ehashfn(NULL,
- be32_to_cpu(laddr), 0,
- be32_to_cpu(faddr), 0);
- return &rds_conn_hash[hash & RDS_CONNECTION_HASH_MASK];
+ return inet_ehashfn(NULL, be32_to_cpu(laddr), 0, be32_to_cpu(faddr), 0);
}

#define rds_conn_info_set(var, test, suffix) do { \
@@ -64,14 +60,14 @@ static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr)
} while (0)

/* rcu read lock must be held or the connection spinlock */
-static struct rds_connection *rds_conn_lookup(struct hlist_head *head,
- __be32 laddr, __be32 faddr,
+static struct rds_connection *rds_conn_lookup(__be32 laddr, __be32 faddr,
struct rds_transport *trans)
{
struct rds_connection *conn, *ret = NULL;
struct hlist_node *pos;
+ unsigned long key = rds_conn_hashfn(laddr, faddr);

- hlist_for_each_entry_rcu(conn, pos, head, c_hash_node) {
+ hash_for_each_possible_rcu(rds_conn_hash, conn, pos, c_hash_node, key) {
if (conn->c_faddr == faddr && conn->c_laddr == laddr &&
conn->c_trans == trans) {
ret = conn;
@@ -117,13 +113,12 @@ static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
int is_outgoing)
{
struct rds_connection *conn, *parent = NULL;
- struct hlist_head *head = rds_conn_bucket(laddr, faddr);
struct rds_transport *loop_trans;
unsigned long flags;
int ret;

rcu_read_lock();
- conn = rds_conn_lookup(head, laddr, faddr, trans);
+ conn = rds_conn_lookup(laddr, faddr, trans);
if (conn && conn->c_loopback && conn->c_trans != &rds_loop_transport &&
!is_outgoing) {
/* This is a looped back IB connection, and we're
@@ -224,13 +219,15 @@ static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
/* Creating normal conn */
struct rds_connection *found;

- found = rds_conn_lookup(head, laddr, faddr, trans);
+ found = rds_conn_lookup(laddr, faddr, trans);
if (found) {
trans->conn_free(conn->c_transport_data);
kmem_cache_free(rds_conn_slab, conn);
conn = found;
} else {
- hlist_add_head_rcu(&conn->c_hash_node, head);
+ unsigned long key = rds_conn_hashfn(laddr, faddr);
+
+ hash_add_rcu(rds_conn_hash, &conn->c_hash_node, key);
rds_cong_add_conn(conn);
rds_conn_count++;
}
@@ -303,7 +300,7 @@ void rds_conn_shutdown(struct rds_connection *conn)
* conn - the reconnect is always triggered by the active peer. */
cancel_delayed_work_sync(&conn->c_conn_w);
rcu_read_lock();
- if (!hlist_unhashed(&conn->c_hash_node)) {
+ if (hash_hashed(&conn->c_hash_node)) {
rcu_read_unlock();
rds_queue_reconnect(conn);
} else {
@@ -329,7 +326,7 @@ void rds_conn_destroy(struct rds_connection *conn)

/* Ensure conn will not be scheduled for reconnect */
spin_lock_irq(&rds_conn_lock);
- hlist_del_init_rcu(&conn->c_hash_node);
+ hash_del(&conn->c_hash_node);
spin_unlock_irq(&rds_conn_lock);
synchronize_rcu();

@@ -375,7 +372,6 @@ static void rds_conn_message_info(struct socket *sock, unsigned int len,
struct rds_info_lengths *lens,
int want_send)
{
- struct hlist_head *head;
struct hlist_node *pos;
struct list_head *list;
struct rds_connection *conn;
@@ -388,27 +384,24 @@ static void rds_conn_message_info(struct socket *sock, unsigned int len,

rcu_read_lock();

- for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
- i++, head++) {
- hlist_for_each_entry_rcu(conn, pos, head, c_hash_node) {
- if (want_send)
- list = &conn->c_send_queue;
- else
- list = &conn->c_retrans;
-
- spin_lock_irqsave(&conn->c_lock, flags);
-
- /* XXX too lazy to maintain counts.. */
- list_for_each_entry(rm, list, m_conn_item) {
- total++;
- if (total <= len)
- rds_inc_info_copy(&rm->m_inc, iter,
- conn->c_laddr,
- conn->c_faddr, 0);
- }
-
- spin_unlock_irqrestore(&conn->c_lock, flags);
+ hash_for_each_rcu(rds_conn_hash, i, pos, conn, c_hash_node) {
+ if (want_send)
+ list = &conn->c_send_queue;
+ else
+ list = &conn->c_retrans;
+
+ spin_lock_irqsave(&conn->c_lock, flags);
+
+ /* XXX too lazy to maintain counts.. */
+ list_for_each_entry(rm, list, m_conn_item) {
+ total++;
+ if (total <= len)
+ rds_inc_info_copy(&rm->m_inc, iter,
+ conn->c_laddr,
+ conn->c_faddr, 0);
}
+
+ spin_unlock_irqrestore(&conn->c_lock, flags);
}
rcu_read_unlock();

@@ -438,7 +431,6 @@ void rds_for_each_conn_info(struct socket *sock, unsigned int len,
size_t item_len)
{
uint64_t buffer[(item_len + 7) / 8];
- struct hlist_head *head;
struct hlist_node *pos;
struct rds_connection *conn;
size_t i;
@@ -448,23 +440,19 @@ void rds_for_each_conn_info(struct socket *sock, unsigned int len,
lens->nr = 0;
lens->each = item_len;

- for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
- i++, head++) {
- hlist_for_each_entry_rcu(conn, pos, head, c_hash_node) {
-
- /* XXX no c_lock usage.. */
- if (!visitor(conn, buffer))
- continue;
-
- /* We copy as much as we can fit in the buffer,
- * but we count all items so that the caller
- * can resize the buffer. */
- if (len >= item_len) {
- rds_info_copy(iter, buffer, item_len);
- len -= item_len;
- }
- lens->nr++;
+ hash_for_each_rcu(rds_conn_hash, i, pos, conn, c_hash_node) {
+ /* XXX no c_lock usage.. */
+ if (!visitor(conn, buffer))
+ continue;
+
+ /* We copy as much as we can fit in the buffer,
+ * but we count all items so that the caller
+ * can resize the buffer. */
+ if (len >= item_len) {
+ rds_info_copy(iter, buffer, item_len);
+ len -= item_len;
}
+ lens->nr++;
}
rcu_read_unlock();
}
@@ -518,6 +506,8 @@ int rds_conn_init(void)
rds_info_register_func(RDS_INFO_RETRANS_MESSAGES,
rds_conn_message_info_retrans);

+ hash_init(rds_conn_hash);
+
return 0;
}

@@ -525,8 +515,6 @@ void rds_conn_exit(void)
{
rds_loop_exit();

- WARN_ON(!hlist_empty(rds_conn_hash));
-
kmem_cache_destroy(rds_conn_slab);

rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info);
--
1.7.8.6