Messages in this thread Patch in this message | | | Date | Wed, 20 Nov 2013 07:08:50 -0500 (EST) | From | Jason Wang <> | Subject | Re: [PATCH net 2/3] virtio-net: fix num calculation on frag skb allocation failure |
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----- 原始邮件 ----- > On Wed, Nov 20, 2013 at 05:07:26PM +0800, Jason Wang wrote: > > We need decrease the rq->num after we can get a buf through > > virtqueue_get_buf() even if we could not allocate frag skb. Otherwise, the > > refill routine won't be triggered under heavy memory stress since the > > driver may > > still think there's enough room. > > > > This bug was introduced by commit 2613af0ed18a11d5c566a81f9a6510b73180660a > > (virtio_net: migrate mergeable rx buffers to page frag allocators). > > > > Cc: Rusty Russell <rusty@rustcorp.com.au> > > Cc: Michael S. Tsirkin <mst@redhat.com> > > Cc: Michael Dalton <mwdalton@google.com> > > Cc: Eric Dumazet <edumazet@google.com> > > Signed-off-by: Jason Wang <jasowang@redhat.com> > > So let's wrap virtqueue_get_buf to make sure we get it right? >
Ok. good idea. > > --- > > The patch was needed for 3.12 stable. > > --- > > drivers/net/virtio_net.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > > index 24fd502..de1d6ca 100644 > > --- a/drivers/net/virtio_net.c > > +++ b/drivers/net/virtio_net.c > > @@ -333,6 +333,7 @@ static int receive_mergeable(struct receive_queue *rq, > > struct sk_buff *head_skb) > > head_skb->dev->stats.rx_length_errors++; > > return -EINVAL; > > } > > + --rq->num; > > if (unlikely(len > MERGE_BUFFER_LEN)) { > > pr_debug("%s: rx error: merge buffer too long\n", > > head_skb->dev->name); > > @@ -367,7 +368,6 @@ static int receive_mergeable(struct receive_queue *rq, > > struct sk_buff *head_skb) > > skb_add_rx_frag(curr_skb, num_skb_frags, page, > > offset, len, MERGE_BUFFER_LEN); > > } > > - --rq->num; > > } > > return 0; > > } > > -- > > 1.8.3.2 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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