From 1788f49548860fa1c861ee3454d47b466c877e43 Mon Sep 17 00:00:00 2001 From: Michael S. Tsirkin Date: Fri, 2 Jul 2010 16:32:55 +0000 Subject: virtio_net: do not reschedule rx refill forever We currently fill all of RX ring, then add_buf returns ENOSPC, which gets mis-detected as an out of memory condition and causes us to reschedule the work, and so on forever. Fix this by oom = err == -ENOMEM; Signed-off-by: Michael S. Tsirkin Signed-off-by: Rusty Russell Cc: stable@kernel.org # .34.x Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'drivers/net/virtio_net.c') diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 1edb7a61983c..ee7571195b10 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -415,7 +415,7 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi, gfp_t gfp) static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp) { int err; - bool oom = false; + bool oom; do { if (vi->mergeable_rx_bufs) @@ -425,10 +425,9 @@ static bool try_fill_recv(struct virtnet_info *vi, gfp_t gfp) else err = add_recvbuf_small(vi, gfp); - if (err < 0) { - oom = true; + oom = err == -ENOMEM; + if (err < 0) break; - } ++vi->num; } while (err > 0); if (unlikely(vi->num > vi->max)) -- cgit v1.2.3-55-g7522 From 58eba97d0774c69b1cf3e5a8ac74419409d1abbf Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 2 Jul 2010 16:34:01 +0000 Subject: virtio_net: fix oom handling on tx 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 Signed-off-by: Rusty Russell (...and avoid TX_BUSY) Cc: stable@kernel.org # .34.x (s/virtqueue_/vi->svq->vq_ops->/) Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'drivers/net/virtio_net.c') diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index ee7571195b10..bb6b67f6b0cc 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -562,7 +562,6 @@ 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); @@ -571,14 +570,20 @@ 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->stats.tx_fifo_errors++; + dev_warn(&dev->dev, + "Unexpected TX queue failure: %d\n", + capacity); + } } - return NETDEV_TX_BUSY; + dev->stats.tx_dropped++; + kfree_skb(skb); + return NETDEV_TX_OK; } virtqueue_kick(vi->svq); -- cgit v1.2.3-55-g7522