From 65dedd7fe1f224e9989181d161e23f0a544d304f Mon Sep 17 00:00:00 2001
From: Chris Mason <chris.mason@oracle.com>
Date: Fri, 3 Feb 2012 11:07:54 -0500
Subject: [PATCH 1/4] RDS: limit the number of times we loop in rds_send_xmit

This will kick the RDS worker thread if we have been looping
too long.

Original commit from 2012 updated to include a change by
Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
that triggers "must_wake" if "rds_ib_recv_refill_one" fails.

Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/rds/ib_recv.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/net/rds/ib_recv.c b/net/rds/ib_recv.c
index 3cae88cbdaa02..1a8a4a760b849 100644
--- a/net/rds/ib_recv.c
+++ b/net/rds/ib_recv.c
@@ -385,6 +385,7 @@ void rds_ib_recv_refill(struct rds_connection *conn, int prefill, gfp_t gfp)
 	unsigned int posted = 0;
 	int ret = 0;
 	bool can_wait = !!(gfp & __GFP_DIRECT_RECLAIM);
+	bool must_wake = false;
 	u32 pos;
 
 	/* the goal here is to just make sure that someone, somewhere
@@ -405,6 +406,7 @@ void rds_ib_recv_refill(struct rds_connection *conn, int prefill, gfp_t gfp)
 		recv = &ic->i_recvs[pos];
 		ret = rds_ib_recv_refill_one(conn, recv, gfp);
 		if (ret) {
+			must_wake = true;
 			break;
 		}
 
@@ -423,6 +425,11 @@ void rds_ib_recv_refill(struct rds_connection *conn, int prefill, gfp_t gfp)
 		}
 
 		posted++;
+
+		if ((posted > 128 && need_resched()) || posted > 8192) {
+			must_wake = true;
+			break;
+		}
 	}
 
 	/* We're doing flow control - update the window. */
@@ -445,10 +452,13 @@ void rds_ib_recv_refill(struct rds_connection *conn, int prefill, gfp_t gfp)
 	 * if we should requeue.
 	 */
 	if (rds_conn_up(conn) &&
-	    ((can_wait && rds_ib_ring_low(&ic->i_recv_ring)) ||
+	    (must_wake ||
+	    (can_wait && rds_ib_ring_low(&ic->i_recv_ring)) ||
 	    rds_ib_ring_empty(&ic->i_recv_ring))) {
 		queue_delayed_work(rds_wq, &conn->c_recv_w, 1);
 	}
+	if (can_wait)
+		cond_resched();
 }
 
 /*

From 356feaad4f7d153ae429f2c7f7900b589dca6801 Mon Sep 17 00:00:00 2001
From: Chris Mason <chris.mason@oracle.com>
Date: Fri, 3 Feb 2012 11:08:51 -0500
Subject: [PATCH 2/4] RDS: don't use GFP_ATOMIC for sk_alloc in rds_create

Signed-off-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Bang Nguyen <bang.nguyen@oracle.com>
Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/rds/af_rds.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/rds/af_rds.c b/net/rds/af_rds.c
index e7b082ac60fd9..2977137c28eb3 100644
--- a/net/rds/af_rds.c
+++ b/net/rds/af_rds.c
@@ -705,7 +705,7 @@ static int rds_create(struct net *net, struct socket *sock, int protocol,
 	if (sock->type != SOCK_SEQPACKET || protocol)
 		return -ESOCKTNOSUPPORT;
 
-	sk = sk_alloc(net, AF_RDS, GFP_ATOMIC, &rds_proto, kern);
+	sk = sk_alloc(net, AF_RDS, GFP_KERNEL, &rds_proto, kern);
 	if (!sk)
 		return -ENOMEM;
 

From 55c70ca00c982fbc0df4c4d3e31747fb73f4ddb5 Mon Sep 17 00:00:00 2001
From: Gerd Rausch <gerd.rausch@oracle.com>
Date: Thu, 11 Jul 2019 12:15:50 -0700
Subject: [PATCH 3/4] net/rds: Add a few missing rds_stat_names entries

In a previous commit, fields were added to "struct rds_statistics"
but array "rds_stat_names" was not updated accordingly.

Please note the inconsistent naming of the string representations
that is done in the name of compatibility
with the Oracle internal code-base.

s_recv_bytes_added_to_socket     -> "recv_bytes_added_to_sock"
s_recv_bytes_removed_from_socket -> "recv_bytes_freed_fromsock"

Fixes: 192a798f5299 ("RDS: add stat for socket recv memory usage")
Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/rds/stats.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/rds/stats.c b/net/rds/stats.c
index 73be187d389ed..6bbab4d74c4fe 100644
--- a/net/rds/stats.c
+++ b/net/rds/stats.c
@@ -76,6 +76,8 @@ static const char *const rds_stat_names[] = {
 	"cong_update_received",
 	"cong_send_error",
 	"cong_send_blocked",
+	"recv_bytes_added_to_sock",
+	"recv_bytes_freed_fromsock",
 };
 
 void rds_stats_info_copy(struct rds_info_iterator *iter,

From 11740ef4482914fcd8c9814ef7ceb7085715e554 Mon Sep 17 00:00:00 2001
From: Andy Grover <andy.grover@oracle.com>
Date: Thu, 13 Jan 2011 11:40:31 -0800
Subject: [PATCH 4/4] rds: check for excessive looping in rds_send_xmit

Original commit from 2011 updated to include a change by
Yuval Shaia <yuval.shaia@oracle.com>
that adds a new statistic counter "send_stuck_rm"
to capture the messages looping exessively
in the send path.

Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/rds/rds.h   |  2 +-
 net/rds/send.c  | 12 ++++++++++++
 net/rds/stats.c |  1 +
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/net/rds/rds.h b/net/rds/rds.h
index f0066d1684993..ad605fd61655e 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -717,7 +717,7 @@ struct rds_statistics {
 	uint64_t	s_cong_send_blocked;
 	uint64_t	s_recv_bytes_added_to_socket;
 	uint64_t	s_recv_bytes_removed_from_socket;
-
+	uint64_t	s_send_stuck_rm;
 };
 
 /* af_rds.c */
diff --git a/net/rds/send.c b/net/rds/send.c
index 031b1e97a4663..9ce552abf9e9c 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -145,6 +145,7 @@ int rds_send_xmit(struct rds_conn_path *cp)
 	LIST_HEAD(to_be_dropped);
 	int batch_count;
 	unsigned long send_gen = 0;
+	int same_rm = 0;
 
 restart:
 	batch_count = 0;
@@ -200,6 +201,17 @@ int rds_send_xmit(struct rds_conn_path *cp)
 
 		rm = cp->cp_xmit_rm;
 
+		if (!rm) {
+			same_rm = 0;
+		} else {
+			same_rm++;
+			if (same_rm >= 4096) {
+				rds_stats_inc(s_send_stuck_rm);
+				ret = -EAGAIN;
+				break;
+			}
+		}
+
 		/*
 		 * If between sending messages, we can send a pending congestion
 		 * map update.
diff --git a/net/rds/stats.c b/net/rds/stats.c
index 6bbab4d74c4fe..9e87da43c0045 100644
--- a/net/rds/stats.c
+++ b/net/rds/stats.c
@@ -78,6 +78,7 @@ static const char *const rds_stat_names[] = {
 	"cong_send_blocked",
 	"recv_bytes_added_to_sock",
 	"recv_bytes_freed_fromsock",
+	"send_stuck_rm",
 };
 
 void rds_stats_info_copy(struct rds_info_iterator *iter,