lkml.org 
[lkml]   [2007]   [Apr]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/8] AF_RXRPC: Lower dead call timeout and fix available call counting on connections
Date
Make a couple of fixes to AF_RXRPC:

(1) The dead call timeout is shortened to 2 seconds. Without this, each
completed call sits around eating up resources for 10 seconds. The calls
need to hang around for a little while in case duplicate packets appear,
but 10 seconds is excessive.

(2) The number of available calls on a connection (conn->avail_calls) wasn't
being decremented when a new call was allocated for a connection that
didn't have any calls in progress. This an occasional BUG occurring when
we tried to find an empty channel slot on a connection that was supposed
to have one available and didn't.

In association with this, more assertions have been added to check this.

Signed-Off-By: David Howells <dhowells@redhat.com>
---

net/rxrpc/ar-call.c | 59 +++++++++++++++++++++++++++++----------------
net/rxrpc/ar-connection.c | 20 ++++++++++++++-
2 files changed, 56 insertions(+), 23 deletions(-)

diff --git a/net/rxrpc/ar-call.c b/net/rxrpc/ar-call.c
index 1d7698a..4d92d88 100644
--- a/net/rxrpc/ar-call.c
+++ b/net/rxrpc/ar-call.c
@@ -19,7 +19,7 @@ struct kmem_cache *rxrpc_call_jar;
LIST_HEAD(rxrpc_calls);
DEFINE_RWLOCK(rxrpc_call_lock);
static unsigned rxrpc_call_max_lifetime = 60;
-static unsigned rxrpc_dead_call_timeout = 10;
+static unsigned rxrpc_dead_call_timeout = 2;

static void rxrpc_destroy_call(struct work_struct *work);
static void rxrpc_call_life_expired(unsigned long _call);
@@ -398,6 +398,7 @@ found_extant_call:
*/
void rxrpc_release_call(struct rxrpc_call *call)
{
+ struct rxrpc_connection *conn = call->conn;
struct rxrpc_sock *rx = call->socket;

_enter("{%d,%d,%d,%d}",
@@ -413,8 +414,7 @@ void rxrpc_release_call(struct rxrpc_call *call)
/* dissociate from the socket
* - the socket's ref on the call is passed to the death timer
*/
- _debug("RELEASE CALL %p (%d CONN %p)",
- call, call->debug_id, call->conn);
+ _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);

write_lock_bh(&rx->call_lock);
if (!list_empty(&call->accept_link)) {
@@ -430,24 +430,42 @@ void rxrpc_release_call(struct rxrpc_call *call)
}
write_unlock_bh(&rx->call_lock);

- if (call->conn->out_clientflag)
- spin_lock(&call->conn->trans->client_lock);
- write_lock_bh(&call->conn->lock);
-
/* free up the channel for reuse */
- if (call->conn->out_clientflag) {
- call->conn->avail_calls++;
- if (call->conn->avail_calls == RXRPC_MAXCALLS)
- list_move_tail(&call->conn->bundle_link,
- &call->conn->bundle->unused_conns);
- else if (call->conn->avail_calls == 1)
- list_move_tail(&call->conn->bundle_link,
- &call->conn->bundle->avail_conns);
+ spin_lock(&conn->trans->client_lock);
+ write_lock_bh(&conn->lock);
+ write_lock(&call->state_lock);
+
+ if (conn->channels[call->channel] == call)
+ conn->channels[call->channel] = NULL;
+
+ if (conn->out_clientflag && conn->bundle) {
+ conn->avail_calls++;
+ switch (conn->avail_calls) {
+ case 1:
+ list_move_tail(&conn->bundle_link,
+ &conn->bundle->avail_conns);
+ case 2 ... RXRPC_MAXCALLS - 1:
+ ASSERT(conn->channels[0] == NULL ||
+ conn->channels[1] == NULL ||
+ conn->channels[2] == NULL ||
+ conn->channels[3] == NULL);
+ break;
+ case RXRPC_MAXCALLS:
+ list_move_tail(&conn->bundle_link,
+ &conn->bundle->unused_conns);
+ ASSERT(conn->channels[0] == NULL &&
+ conn->channels[1] == NULL &&
+ conn->channels[2] == NULL &&
+ conn->channels[3] == NULL);
+ break;
+ default:
+ printk(KERN_ERR "RxRPC: conn->avail_calls=%d\n",
+ conn->avail_calls);
+ BUG();
+ }
}

- write_lock(&call->state_lock);
- if (call->conn->channels[call->channel] == call)
- call->conn->channels[call->channel] = NULL;
+ spin_unlock(&conn->trans->client_lock);

if (call->state < RXRPC_CALL_COMPLETE &&
call->state != RXRPC_CALL_CLIENT_FINAL_ACK) {
@@ -458,10 +476,9 @@ void rxrpc_release_call(struct rxrpc_call *call)
rxrpc_queue_call(call);
}
write_unlock(&call->state_lock);
- write_unlock_bh(&call->conn->lock);
- if (call->conn->out_clientflag)
- spin_unlock(&call->conn->trans->client_lock);
+ write_unlock_bh(&conn->lock);

+ /* clean up the Rx queue */
if (!skb_queue_empty(&call->rx_queue) ||
!skb_queue_empty(&call->rx_oos_queue)) {
struct rxrpc_skb_priv *sp;
diff --git a/net/rxrpc/ar-connection.c b/net/rxrpc/ar-connection.c
index 2d0efaa..5bb2673 100644
--- a/net/rxrpc/ar-connection.c
+++ b/net/rxrpc/ar-connection.c
@@ -356,7 +356,7 @@ static int rxrpc_connect_exclusive(struct rxrpc_sock *rx,
conn->out_clientflag = RXRPC_CLIENT_INITIATED;
conn->cid = 0;
conn->state = RXRPC_CONN_CLIENT;
- conn->avail_calls = RXRPC_MAXCALLS;
+ conn->avail_calls = RXRPC_MAXCALLS - 1;
conn->security_level = rx->min_sec_level;
conn->key = key_get(rx->key);

@@ -447,6 +447,11 @@ int rxrpc_connect_call(struct rxrpc_sock *rx,
if (--conn->avail_calls == 0)
list_move(&conn->bundle_link,
&bundle->busy_conns);
+ ASSERTCMP(conn->avail_calls, <, RXRPC_MAXCALLS);
+ ASSERT(conn->channels[0] == NULL ||
+ conn->channels[1] == NULL ||
+ conn->channels[2] == NULL ||
+ conn->channels[3] == NULL);
atomic_inc(&conn->usage);
break;
}
@@ -456,6 +461,12 @@ int rxrpc_connect_call(struct rxrpc_sock *rx,
conn = list_entry(bundle->unused_conns.next,
struct rxrpc_connection,
bundle_link);
+ ASSERTCMP(conn->avail_calls, ==, RXRPC_MAXCALLS);
+ conn->avail_calls = RXRPC_MAXCALLS - 1;
+ ASSERT(conn->channels[0] == NULL &&
+ conn->channels[1] == NULL &&
+ conn->channels[2] == NULL &&
+ conn->channels[3] == NULL);
atomic_inc(&conn->usage);
list_move(&conn->bundle_link, &bundle->avail_conns);
break;
@@ -512,7 +523,7 @@ int rxrpc_connect_call(struct rxrpc_sock *rx,
candidate->state = RXRPC_CONN_CLIENT;
candidate->avail_calls = RXRPC_MAXCALLS;
candidate->security_level = rx->min_sec_level;
- candidate->key = key_get(rx->key);
+ candidate->key = key_get(bundle->key);

ret = rxrpc_init_client_conn_security(candidate);
if (ret < 0) {
@@ -555,6 +566,10 @@ int rxrpc_connect_call(struct rxrpc_sock *rx,
for (chan = 0; chan < RXRPC_MAXCALLS; chan++)
if (!conn->channels[chan])
goto found_channel;
+ ASSERT(conn->channels[0] == NULL ||
+ conn->channels[1] == NULL ||
+ conn->channels[2] == NULL ||
+ conn->channels[3] == NULL);
BUG();

found_channel:
@@ -567,6 +582,7 @@ found_channel:
_net("CONNECT client on conn %d chan %d as call %x",
conn->debug_id, chan, ntohl(call->call_id));

+ ASSERTCMP(conn->avail_calls, <, RXRPC_MAXCALLS);
spin_unlock(&trans->client_lock);

rxrpc_add_call_ID_to_conn(conn, call);
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-04-11 21:17    [W:0.063 / U:0.060 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site