diff options
| author | Andy Grover <andy.grover@oracle.com> | 2010-03-23 17:39:07 -0700 |
|---|---|---|
| committer | Andy Grover <andy.grover@oracle.com> | 2010-09-08 18:12:12 -0700 |
| commit | 049ee3f500954176a87f22e6ee3e98aecb1b8958 (patch) | |
| tree | 5dfd8cf3e6d9a7a15e80f6ddee7f4ce7c4aa7a8c /net/rds/connection.c | |
| parent | f17a1a55fb672d7f64be7f2e940ef5669e5efa0a (diff) | |
| download | linux-049ee3f500954176a87f22e6ee3e98aecb1b8958.tar.gz | |
RDS: Change send lock from a mutex to a spinlock
This change allows us to call rds_send_xmit() from a tasklet, which is crucial to our new operating model. * Change c_send_lock to a spinlock * Update stats fields "sem_" to "_lock" * Remove unneeded rds_conn_is_sending() About locking between shutdown and send -- send checks if the connection is up. Shutdown puts the connection into DISCONNECTING. After this, all threads entering send will exit immediately. However, a thread could be *in* send_xmit(), so shutdown acquires the c_send_lock to ensure everyone is out before proceeding with connection shutdown. Signed-off-by: Andy Grover <andy.grover@oracle.com>
Diffstat (limited to 'net/rds/connection.c')
| -rw-r--r-- | net/rds/connection.c | 22 |
1 files changed, 6 insertions, 16 deletions
diff --git a/net/rds/connection.c b/net/rds/connection.c index 88bcaf3f3e16..56aebe444ad3 100644 --- a/net/rds/connection.c +++ b/net/rds/connection.c @@ -62,18 +62,6 @@ static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr) var |= RDS_INFO_CONNECTION_FLAG_##suffix; \ } while (0) -static inline int rds_conn_is_sending(struct rds_connection *conn) -{ - int ret = 0; - - if (!mutex_trylock(&conn->c_send_lock)) - ret = 1; - else - mutex_unlock(&conn->c_send_lock); - - return ret; -} - static struct rds_connection *rds_conn_lookup(struct hlist_head *head, __be32 laddr, __be32 faddr, struct rds_transport *trans) @@ -158,7 +146,7 @@ static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr, spin_lock_init(&conn->c_lock); conn->c_next_tx_seq = 1; - mutex_init(&conn->c_send_lock); + spin_lock_init(&conn->c_send_lock); INIT_LIST_HEAD(&conn->c_send_queue); INIT_LIST_HEAD(&conn->c_retrans); @@ -283,10 +271,12 @@ void rds_conn_shutdown(struct rds_connection *conn) } mutex_unlock(&conn->c_cm_lock); - mutex_lock(&conn->c_send_lock); + /* verify everybody's out of rds_send_xmit() */ + spin_lock_irq(&conn->c_send_lock); + spin_unlock_irq(&conn->c_send_lock); + conn->c_trans->conn_shutdown(conn); rds_conn_reset(conn); - mutex_unlock(&conn->c_send_lock); if (!rds_conn_transition(conn, RDS_CONN_DISCONNECTING, RDS_CONN_DOWN)) { /* This can happen - eg when we're in the middle of tearing @@ -476,7 +466,7 @@ static int rds_conn_info_visitor(struct rds_connection *conn, cinfo->flags = 0; rds_conn_info_set(cinfo->flags, - rds_conn_is_sending(conn), SENDING); + spin_is_locked(&conn->c_send_lock), SENDING); /* XXX Future: return the state rather than these funky bits */ rds_conn_info_set(cinfo->flags, atomic_read(&conn->c_state) == RDS_CONN_CONNECTING, |