RDS: Remove unsignaled_bytes sysctl

Removed unsignaled_bytes sysctl and code to signal
based on it. I believe unsignaled_wrs is more than
sufficient for our purposes.
Signed-off-by: Andy Grover <andy.grover@oracle.com>

net/rds/ib.h

@@ -138,7 +138,6 @@ struct rds_ib_connection {
 
 	/* Batched completions */
 	unsigned int		i_unsignaled_wrs;
-	long			i_unsignaled_bytes;
 };
 
 /* This assumes that atomic_t is at least 32 bits */

net/rds/ib_send.c

@@ -518,7 +518,6 @@ int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
 		}
 
 		ic->i_unsignaled_wrs = rds_ib_sysctl_max_unsig_wrs;
-		ic->i_unsignaled_bytes = rds_ib_sysctl_max_unsig_bytes;
 		rds_message_addref(rm);
 		ic->i_rm = rm;
 
@@ -617,12 +616,6 @@ int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
 			send->s_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
 		}
 
-		ic->i_unsignaled_bytes -= len;
-		if (ic->i_unsignaled_bytes <= 0) {
-			ic->i_unsignaled_bytes = rds_ib_sysctl_max_unsig_bytes;
-			send->s_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
-		}
-
 		/*
 		 * Always signal the last one if we're stopping due to flow control.
 		 */

net/rds/ib_sysctl.c

@@ -49,10 +49,6 @@ unsigned long rds_ib_sysctl_max_unsig_wrs = 16;
 static unsigned long rds_ib_sysctl_max_unsig_wr_min = 1;
 static unsigned long rds_ib_sysctl_max_unsig_wr_max = 64;
 
-unsigned long rds_ib_sysctl_max_unsig_bytes = (16 << 20);
-static unsigned long rds_ib_sysctl_max_unsig_bytes_min = 1;
-static unsigned long rds_ib_sysctl_max_unsig_bytes_max = ~0UL;
-
 /*
  * This sysctl does nothing.
  *
@@ -93,15 +89,6 @@ ctl_table rds_ib_sysctl_table[] = {
 		.extra1		= &rds_ib_sysctl_max_unsig_wr_min,
 		.extra2		= &rds_ib_sysctl_max_unsig_wr_max,
 	},
-	{
-		.procname       = "max_unsignaled_bytes",
-		.data		= &rds_ib_sysctl_max_unsig_bytes,
-		.maxlen         = sizeof(unsigned long),
-		.mode           = 0644,
-		.proc_handler   = proc_doulongvec_minmax,
-		.extra1		= &rds_ib_sysctl_max_unsig_bytes_min,
-		.extra2		= &rds_ib_sysctl_max_unsig_bytes_max,
-	},
 	{
 		.procname       = "max_recv_allocation",
 		.data		= &rds_ib_sysctl_max_recv_allocation,