From: Andy Grover <andy.grover@oracle.com>
Date: Thu, 13 Jan 2011 19:40:31 +0000 (-0800)
Subject: rds: check for excessive looping in rds_send_xmit
X-Git-Tag: v4.1.12-92~319^2^2~2^2~55
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=b7ca756ccba06bb63f5ba555f2b6ba2e01e70940;p=users%2Fjedix%2Flinux-maple.git

rds: check for excessive looping in rds_send_xmit

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Bang Nguyen <bang.nguyen@oracle.com>
---

diff --git a/net/rds/send.c b/net/rds/send.c
index ed1ad6962baa..e1f7f0585b27 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -134,6 +134,7 @@ int rds_send_xmit(struct rds_connection *conn)
 	struct scatterlist *sg;
 	int ret = 0;
 	LIST_HEAD(to_be_dropped);
+	int same_rm = 0;
 
 restart:
 
@@ -171,6 +172,18 @@ restart:
 
 		rm = conn->c_xmit_rm;
 
+		if (!rm) {
+			same_rm = 0;
+		} else {
+			same_rm++;
+			if ((same_rm >= 4096) && printk_ratelimit()) {
+				printk(KERN_ERR "RDS: Stuck rm\n");
+				cond_resched();
+				ret = -EAGAIN;
+				break;
+			}
+		}
+
 		/*
 		 * If between sending messages, we can send a pending congestion
 		 * map update.