[PATCH for-2.6.35] virtio_net: fix oom handling on tx
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2010-06-10 15:25:55
Subsystem:
networking drivers, the rest, virtio net driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, "Michael S. Tsirkin", Jason Wang
virtio net will never try to overflow the TX ring, so the only reason add_buf may fail is out of memory. Thus, we can not stop the device until some request completes - there's no guarantee anything at all is outstanding. Make the error message clearer as well: error here does not indicate queue full. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- drivers/net/virtio_net.c | 15 ++++++++------- 1 files changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 85615a3..e48a06f 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c@@ -563,7 +563,6 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) struct virtnet_info *vi = netdev_priv(dev); int capacity; -again: /* Free up any pending old buffers before queueing new ones. */ free_old_xmit_skbs(vi);
@@ -572,12 +571,14 @@ again: /* This can happen with OOM and indirect buffers. */ if (unlikely(capacity < 0)) { - netif_stop_queue(dev); - dev_warn(&dev->dev, "Unexpected full queue\n"); - if (unlikely(!virtqueue_enable_cb(vi->svq))) { - virtqueue_disable_cb(vi->svq); - netif_start_queue(dev); - goto again; + if (net_ratelimit()) { + if (likely(capacity == -ENOMEM)) + dev_warn(&dev->dev, + "TX queue failure: out of memory\n"); + else + dev_warn(&dev->dev, + "Unexpected TX queue failure: %d\n", + capacity); } return NETDEV_TX_BUSY; }
--
1.7.1.12.g42b7f