RDS: only put sockets that have seen congestion on the poll_waitq
rds_poll_waitq's listeners will be awoken if we receive a congestion
notification. Bad performance may result because *all* polled sockets
contend for this single lock. However, it should not be necessary to
wake pollers when a congestion update arrives if they have never
experienced congestion, and not putting these on the waitq will
hopefully greatly reduce contention.
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rds/rds.h b/net/rds/rds.h
index 85d6f89..4bec6e2 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -388,6 +388,8 @@
/* flag indicating we were congested or not */
int rs_congested;
+ /* seen congestion (ENOBUFS) when sending? */
+ int rs_seen_congestion;
/* rs_lock protects all these adjacent members before the newline */
spinlock_t rs_lock;