[PATCH 07/15] RDS: use rds_send_xmit() state instead of RDS_LL_SEND_FULL

From: Santosh Shilimkar
Date: Sat Sep 19 2015 - 19:07:49 EST


In Transport indepedent rds_sendmsg(), we shouldn't make decisions based
on RDS_LL_SEND_FULL which is used to manage the ring for RDMA based
transports. We can safely issue rds_send_xmit() and the using its
return value take decision on deferred work. This will also fix
the scenario where at times we are seeing connections stuck with
the LL_SEND_FULL bit getting set and never cleared.

We kick krdsd after any time we see -ENOMEM or -EAGAIN from the
ring allocation code.

Signed-off-by: Santosh Shilimkar <ssantosh@xxxxxxxxxx>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx>
---
net/rds/send.c | 10 ++++++----
net/rds/threads.c | 2 ++
2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/net/rds/send.c b/net/rds/send.c
index f1e709c..9d8b52d 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -1122,8 +1122,9 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
*/
rds_stats_inc(s_send_queued);

- if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags))
- rds_send_xmit(conn);
+ ret = rds_send_xmit(conn);
+ if (ret == -ENOMEM || ret == -EAGAIN)
+ queue_delayed_work(rds_wq, &conn->c_send_w, 1);

rds_message_put(rm);
return payload_len;
@@ -1179,8 +1180,9 @@ rds_send_pong(struct rds_connection *conn, __be16 dport)
rds_stats_inc(s_send_queued);
rds_stats_inc(s_send_pong);

- if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags))
- queue_delayed_work(rds_wq, &conn->c_send_w, 0);
+ ret = rds_send_xmit(conn);
+ if (ret == -ENOMEM || ret == -EAGAIN)
+ queue_delayed_work(rds_wq, &conn->c_send_w, 1);

rds_message_put(rm);
return 0;
diff --git a/net/rds/threads.c b/net/rds/threads.c
index dc2402e..454aa6d 100644
--- a/net/rds/threads.c
+++ b/net/rds/threads.c
@@ -162,7 +162,9 @@ void rds_send_worker(struct work_struct *work)
int ret;

if (rds_conn_state(conn) == RDS_CONN_UP) {
+ clear_bit(RDS_LL_SEND_FULL, &conn->c_flags);
ret = rds_send_xmit(conn);
+ cond_resched();
rdsdebug("conn %p ret %d\n", conn, ret);
switch (ret) {
case -EAGAIN:
--
1.9.1

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