From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Tue, 18 Jul 2017 07:38:45 +0000 (+0200)
Subject: 4.9-stable patches
X-Git-Tag: v4.12.3~31
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f979a5ac584bd914e4a9cf31ee807990d00c773c;p=thirdparty%2Fkernel%2Fstable-queue.git

4.9-stable patches

added patches:
	series
	xen-netfront-rework-the-fix-for-rx-stall-during-oom-and-network-stress.patch
---

diff --git a/queue-4.9/series b/queue-4.9/series
new file mode 100644
index 00000000000..66b41553f86
--- /dev/null
+++ b/queue-4.9/series
@@ -0,0 +1 @@
+xen-netfront-rework-the-fix-for-rx-stall-during-oom-and-network-stress.patch
diff --git a/queue-4.9/xen-netfront-rework-the-fix-for-rx-stall-during-oom-and-network-stress.patch b/queue-4.9/xen-netfront-rework-the-fix-for-rx-stall-during-oom-and-network-stress.patch
new file mode 100644
index 00000000000..ab2d5be0aee
--- /dev/null
+++ b/queue-4.9/xen-netfront-rework-the-fix-for-rx-stall-during-oom-and-network-stress.patch
@@ -0,0 +1,66 @@
+From 538d92912d3190a1dd809233a0d57277459f37b2 Mon Sep 17 00:00:00 2001
+From: Vineeth Remanan Pillai <vineethp@amazon.com>
+Date: Tue, 7 Feb 2017 18:59:01 +0000
+Subject: xen-netfront: Rework the fix for Rx stall during OOM and network stress
+
+From: Vineeth Remanan Pillai <vineethp@amazon.com>
+
+commit 538d92912d3190a1dd809233a0d57277459f37b2 upstream.
+
+The commit 90c311b0eeea ("xen-netfront: Fix Rx stall during network
+stress and OOM") caused the refill timer to be triggerred almost on
+all invocations of xennet_alloc_rx_buffers for certain workloads.
+This reworks the fix by reverting to the old behaviour and taking into
+consideration the skb allocation failure. Refill timer is now triggered
+on insufficient requests or skb allocation failure.
+
+Signed-off-by: Vineeth Remanan Pillai <vineethp@amazon.com>
+Fixes: 90c311b0eeea (xen-netfront: Fix Rx stall during network stress and OOM)
+Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
+Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Cc: Eduardo Valentin <eduval@amazon.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/net/xen-netfront.c |   14 +++++++++++---
+ 1 file changed, 11 insertions(+), 3 deletions(-)
+
+--- a/drivers/net/xen-netfront.c
++++ b/drivers/net/xen-netfront.c
+@@ -281,6 +281,7 @@ static void xennet_alloc_rx_buffers(stru
+ {
+ 	RING_IDX req_prod = queue->rx.req_prod_pvt;
+ 	int notify;
++	int err = 0;
+ 
+ 	if (unlikely(!netif_carrier_ok(queue->info->netdev)))
+ 		return;
+@@ -295,8 +296,10 @@ static void xennet_alloc_rx_buffers(stru
+ 		struct xen_netif_rx_request *req;
+ 
+ 		skb = xennet_alloc_one_rx_buffer(queue);
+-		if (!skb)
++		if (!skb) {
++			err = -ENOMEM;
+ 			break;
++		}
+ 
+ 		id = xennet_rxidx(req_prod);
+ 
+@@ -320,8 +323,13 @@ static void xennet_alloc_rx_buffers(stru
+ 
+ 	queue->rx.req_prod_pvt = req_prod;
+ 
+-	/* Not enough requests? Try again later. */
+-	if (req_prod - queue->rx.sring->req_prod < NET_RX_SLOTS_MIN) {
++	/* Try again later if there are not enough requests or skb allocation
++	 * failed.
++	 * Enough requests is quantified as the sum of newly created slots and
++	 * the unconsumed slots at the backend.
++	 */
++	if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
++	    unlikely(err)) {
+ 		mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
+ 		return;
+ 	}