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authorMichael S. Tsirkin <mst@redhat.com>2010-11-04 14:24:24 +0200
committerRusty Russell <rusty@rustcorp.com.au>2010-11-24 15:21:11 +1030
commit7ae4b866f86f9ab7b99484b56dd303a860ad1cc9 (patch)
tree247cd281bdf2e892180ff3407377d0a212c30016
parentdfd62d1d84d83f9421792c78bcf72de9bc2bb603 (diff)
downloadop-kernel-dev-7ae4b866f86f9ab7b99484b56dd303a860ad1cc9.zip
op-kernel-dev-7ae4b866f86f9ab7b99484b56dd303a860ad1cc9.tar.gz
virtio: return correct capacity to users
We can't rely on indirect buffers for capacity calculations because they need a memory allocation which might fail. In particular, virtio_net can get into this situation under stress, and it drops packets and performs badly. So return the number of buffers we can guarantee users. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reported-By: Krishna Kumar2 <krkumar2@in.ibm.com>
-rw-r--r--drivers/virtio/virtio_ring.c3
1 files changed, 0 insertions, 3 deletions
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 1475ed6..cc2f73e 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -230,9 +230,6 @@ add_head:
pr_debug("Added buffer head %i to %p\n", head, vq);
END_USE(vq);
- /* If we're indirect, we can fit many (assuming not OOM). */
- if (vq->indirect)
- return vq->num_free ? vq->vring.num : 0;
return vq->num_free;
}
EXPORT_SYMBOL_GPL(virtqueue_add_buf_gfp);
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