Re: [PATCH] virtio_net: avoid BUG_ON() with large packets when CONFIG_DEBUG_SG=y
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2010-03-31 09:21:23
On Tue, Mar 30, 2010 at 03:26:35PM +1030, Rusty Russell wrote:
AFAICT only weird kvm setups and lguest traverse this code path now. Signed-off-by: Rusty Russell <redacted>
vhost still lacks support mergeable buffers so it uses this path.
quoted hunk ↗ jump to hunk
--- drivers/net/virtio_net.c | 3 +++ 1 file changed, 3 insertions(+)diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c@@ -351,6 +351,9 @@ static int add_recvbuf_big(struct virtne char *p; int i, err, offset; + /* This is a waste of cycles, but satisfies CONFIG_DEBUG_SG. */ + sg_init_table(sg, ARRAY_SIZE(sg)); +
How about moving sg into virtnet_info? This way we could call this only once, right?
/* page in sg[MAX_SKB_FRAGS + 1] is list tail */
for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
first = get_a_page(vi, gfp);