remove function pointer casts and constify function tables

Commit Message

J. Bruce Fields May 31, 2017, 9:09 p.m. UTC

On Tue, May 30, 2017 at 07:26:37PM +0300, Michael S. Tsirkin wrote:
> On Fri, May 26, 2017 at 03:31:33PM -0400, [e-mail] wrote:
> > Looks like the culprit is very likely d85b758f72b0 "virtio_net: fix
> > support for small rings".
> > 
> > After that patch, my NFS server VM stops responding to packets after a
> > few minutes of testing.  Before that patch, my server keeps working.
> > 
> > --b.
> 
> Others complained about that too.
> I'm still trying to reproduce though.
> 
> Meanwhile, could you please locate this line of code:
> +               vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
> 
> and add something like
>         printk(KERN_ERR, "min buf = 0x%x expected 0x%x size 0x%x big %d\n",
>                vi->rq[i].min_buf_len, GOOD_PACKET_LEN,
>                virtqueue_get_vring_size(vi->rq[i].vq),
>                (int)vi->big_packets);
> 
> after it?
> Then boot and capture the output.

Doesn't look like that code's run on boot; apply the below, boot, and:

 $ dmesg|grep expected

gives no output.

--b.


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Comments

J. Bruce Fields May 31, 2017, 9:15 p.m. UTC | #1

On Wed, May 31, 2017 at 05:09:23PM -0400, [e-mail] wrote:
> On Tue, May 30, 2017 at 07:26:37PM +0300, Michael S. Tsirkin wrote:
> > On Fri, May 26, 2017 at 03:31:33PM -0400, [e-mail] wrote:
> > > Looks like the culprit is very likely d85b758f72b0 "virtio_net: fix
> > > support for small rings".
> > > 
> > > After that patch, my NFS server VM stops responding to packets after a
> > > few minutes of testing.  Before that patch, my server keeps working.
> > > 
> > > --b.
> > 
> > Others complained about that too.
> > I'm still trying to reproduce though.
> > 
> > Meanwhile, could you please locate this line of code:
> > +               vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
> > 
> > and add something like
> >         printk(KERN_ERR, "min buf = 0x%x expected 0x%x size 0x%x big %d\n",
> >                vi->rq[i].min_buf_len, GOOD_PACKET_LEN,
> >                virtqueue_get_vring_size(vi->rq[i].vq),
> >                (int)vi->big_packets);
> > 
> > after it?
> > Then boot and capture the output.
> 
> Doesn't look like that code's run on boot; apply the below, boot, and:

Whoops, no, just a typo in the printk.  Here you go:

	min buf = 0x101 expected 0x5ee size 0x100 big 1

--b.
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Patch

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 9320d96a1632..b10014f7b480 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2212,6 +2212,10 @@  static int virtnet_find_vqs(struct virtnet_info *vi)
        for (i = 0; i < vi->max_queue_pairs; i++) {
                vi->rq[i].vq = vqs[rxq2vq(i)];
                vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq);
+               printk(KERN_ERR, "min buf = 0x%x expected 0x%x size 0x%x big %d\n",
+                               vi->rq[i].min_buf_len, GOOD_PACKET_LEN,
+                               virtqueue_get_vring_size(vi->rq[i].vq),
+                               (int)vi->big_packets);
                vi->sq[i].vq = vqs[txq2vq(i)];
        }