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authorVineeth Remanan Pillai <vineethp@amazon.com>2017-02-07 18:59:01 +0000
committerDavid S. Miller <davem@davemloft.net>2017-02-09 16:34:05 -0500
commit538d92912d3190a1dd809233a0d57277459f37b2 (patch)
tree3a0ff3c7ae5e688124425606039b8ae960e5d5de
parent6d9f66ac7fec2a6ccd649e5909806dfe36f1fc25 (diff)
xen-netfront: Rework the fix for Rx stall during OOM and network stress
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>
-rw-r--r--drivers/net/xen-netfront.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 8315fe73ecd0..9dba69731f30 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -281,6 +281,7 @@ static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
{
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(struct netfront_queue *queue)
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(struct netfront_queue *queue)
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;
}