> On (Fri) 02 Nov 2012 [09:52:08], Rusty Russell wrote:
> > Amit Shah <amit.s...@redhat.com> writes:
> > > On (Tue) 23 Oct 2012 [12:17:49], Rusty Russell wrote:
> > >> sjur.brandel...@stericsson.com writes:
> > >> > From: Sjur Brændeland <sjur.brandel...@stericsson.com>
> > >
> > >> > @@ -1415,7 +1524,16 @@ static void remove_port_data(struct port
> *port)
> > >> >
> > >> >        /* Remove buffers we queued up for the Host to send us data in. 
> > >> > */
> > >> >        while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
> > >> > -              free_buf(buf);
> > >> > +              free_buf(buf, true);
> > >> > +
> > >> > +      /*
> > >> > +       * Remove buffers from out queue for rproc-serial. We
> cannot afford
> > >> > +       * to leak any DMA mem, so reclaim this memory even if this
> might be
> > >> > +       * racy for the remote processor.
> > >> > +       */
> > >> > +      if (is_rproc_serial(port->portdev->vdev))
> > >> > +              while ((buf = virtqueue_detach_unused_buf(port-
> >out_vq)))
> > >> > +                      free_buf(buf, true);
> > >> >  }
> > >>
> > >> This seems wrong; either this is needed even if !is_rproc_serial(), or
> > >> it's not necessary as the out_vq is empty.
> > >>
> > >> Every path I can see has the device reset (in which case the queues
> > >> should not be active), or we got a VIRTIO_CONSOLE_PORT_REMOVE
> event (in
> > >> which case, the same).
> > >>
> > >> I think we can have non-blocking writes which could leave buffers in
> > >> out_vq: Amit?
> > >
> > > Those get 'reclaimed' just above this hunk:
> > >
> > >
> > > static void remove_port_data(struct port *port)
> > > {
> > >   struct port_buffer *buf;
> > >
> > >   /* Remove unused data this port might have received. */
> > >   discard_port_data(port);
> > >
> > >   reclaim_consumed_buffers(port);
> > >
> > >   /* Remove buffers we queued up for the Host to send us data in. */
> > >   while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
> > >         free_buf(buf, true);
> >
> > No, that's pending input buffers, not output buffers.
> 
> You're right.  Nice catch.
> 
> Sjur, can you remove the WARN_ON in your latest series, even generic
> ports may have buffers in the outq.

Sure, I can respin the patch and remove the WARN_ON().

> It'll also need to be done in the port_fops_release() function.  Let
> me know if you prefer I send a patch instead.

I can have a go at this, as I have to respin the patch anyway.

Thanks,
Sjur

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

Reply via email to