[PATCH net-next 1/3] rxrpc: Set connection expiry on idle, not put

[David Howells]

Set the connection expiry time when a connection becomes idle rather than
doing this in rxrpc_put_connection().  This makes the put path more
efficient (it is likely to be called occasionally whilst a connection has
outstanding calls because active workqueue items needs to be given a ref).

The time is also preset in the connection allocator in case the connection
never gets used.

Signed-off-by: David Howells <dhowe...@redhat.com>
---

 net/rxrpc/ar-internal.h |   11 +++++++++--
 net/rxrpc/conn_object.c |   42 +++++++++++++++++-------------------------
 2 files changed, 26 insertions(+), 27 deletions(-)

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 8cb517fbbd23..66c917077880 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -313,7 +313,7 @@ struct rxrpc_connection {
        struct rxrpc_crypt      csum_iv;        /* packet checksum base */
        unsigned long           flags;
        unsigned long           events;
-       unsigned long           put_time;       /* Time at which last put */
+       unsigned long           idle_timestamp; /* Time at which last became 
idle */
        spinlock_t              state_lock;     /* state-change lock */
        atomic_t                usage;
        enum rxrpc_conn_proto_state state : 8;  /* current state of connection 
*/
@@ -565,7 +565,7 @@ struct rxrpc_connection *rxrpc_find_connection_rcu(struct 
rxrpc_local *,
                                                   struct sk_buff *);
 void __rxrpc_disconnect_call(struct rxrpc_call *);
 void rxrpc_disconnect_call(struct rxrpc_call *);
-void rxrpc_put_connection(struct rxrpc_connection *);
+void __rxrpc_put_connection(struct rxrpc_connection *);
 void __exit rxrpc_destroy_all_connections(void);
 
 static inline bool rxrpc_conn_is_client(const struct rxrpc_connection *conn)
@@ -589,6 +589,13 @@ struct rxrpc_connection *rxrpc_get_connection_maybe(struct 
rxrpc_connection *con
        return atomic_inc_not_zero(&conn->usage) ? conn : NULL;
 }
 
+static inline void rxrpc_put_connection(struct rxrpc_connection *conn)
+{
+       if (conn && atomic_dec_return(&conn->usage) == 1)
+               __rxrpc_put_connection(conn);
+}
+
+
 static inline bool rxrpc_queue_conn(struct rxrpc_connection *conn)
 {
        if (!rxrpc_get_connection_maybe(conn))
diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c
index 6a5a17efc538..743f0bb4aaa8 100644
--- a/net/rxrpc/conn_object.c
+++ b/net/rxrpc/conn_object.c
@@ -56,6 +56,7 @@ struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
                atomic_set(&conn->avail_chans, RXRPC_MAXCALLS);
                conn->size_align = 4;
                conn->header_size = sizeof(struct rxrpc_wire_header);
+               conn->idle_timestamp = jiffies;
        }
 
        _leave(" = %p{%d}", conn, conn ? conn->debug_id : 0);
@@ -191,29 +192,16 @@ void rxrpc_disconnect_call(struct rxrpc_call *call)
        spin_unlock(&conn->channel_lock);
 
        call->conn = NULL;
+       conn->idle_timestamp = jiffies;
        rxrpc_put_connection(conn);
 }
 
 /*
  * release a virtual connection
  */
-void rxrpc_put_connection(struct rxrpc_connection *conn)
+void __rxrpc_put_connection(struct rxrpc_connection *conn)
 {
-       if (!conn)
-               return;
-
-       _enter("%p{u=%d,d=%d}",
-              conn, atomic_read(&conn->usage), conn->debug_id);
-
-       ASSERTCMP(atomic_read(&conn->usage), >, 1);
-
-       conn->put_time = ktime_get_seconds();
-       if (atomic_dec_return(&conn->usage) == 1) {
-               _debug("zombie");
-               rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
-       }
-
-       _leave("");
+       rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
 }
 
 /*
@@ -248,14 +236,14 @@ static void rxrpc_destroy_connection(struct rcu_head *rcu)
 static void rxrpc_connection_reaper(struct work_struct *work)
 {
        struct rxrpc_connection *conn, *_p;
-       unsigned long reap_older_than, earliest, put_time, now;
+       unsigned long reap_older_than, earliest, idle_timestamp, now;
 
        LIST_HEAD(graveyard);
 
        _enter("");
 
-       now = ktime_get_seconds();
-       reap_older_than =  now - rxrpc_connection_expiry;
+       now = jiffies;
+       reap_older_than = now - rxrpc_connection_expiry * HZ;
        earliest = ULONG_MAX;
 
        write_lock(&rxrpc_connection_lock);
@@ -264,10 +252,14 @@ static void rxrpc_connection_reaper(struct work_struct 
*work)
                if (likely(atomic_read(&conn->usage) > 1))
                        continue;
 
-               put_time = READ_ONCE(conn->put_time);
-               if (time_after(put_time, reap_older_than)) {
-                       if (time_before(put_time, earliest))
-                               earliest = put_time;
+               idle_timestamp = READ_ONCE(conn->idle_timestamp);
+               _debug("reap CONN %d { u=%d,t=%ld }",
+                      conn->debug_id, atomic_read(&conn->usage),
+                      (long)reap_older_than - (long)idle_timestamp);
+
+               if (time_after(idle_timestamp, reap_older_than)) {
+                       if (time_before(idle_timestamp, earliest))
+                               earliest = idle_timestamp;
                        continue;
                }
 
@@ -288,9 +280,9 @@ static void rxrpc_connection_reaper(struct work_struct 
*work)
 
        if (earliest != ULONG_MAX) {
                _debug("reschedule reaper %ld", (long) earliest - now);
-               ASSERTCMP(earliest, >, now);
+               ASSERT(time_after(earliest, now));
                rxrpc_queue_delayed_work(&rxrpc_connection_reap,
-                                        (earliest - now) * HZ);
+                                        earliest - now);
        }
 
        while (!list_empty(&graveyard)) {