Re: [PATCH v5 2/2] virtio-net: use mtu size as buffer length for big packets

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Sep 07, 2022 at 03:36:16PM -0400, Michael S. Tsirkin wrote:
> On Wed, Sep 07, 2022 at 07:27:16PM +0000, Parav Pandit wrote:
> > 
> > > From: Michael S. Tsirkin <mst@redhat.com>
> > > Sent: Wednesday, September 7, 2022 3:24 PM
> > > 
> > > On Wed, Sep 07, 2022 at 07:18:06PM +0000, Parav Pandit wrote:
> > > >
> > > > > From: Michael S. Tsirkin <mst@redhat.com>
> > > > > Sent: Wednesday, September 7, 2022 3:12 PM
> > > >
> > > > > > Because of shallow queue of 16 entries deep.
> > > > >
> > > > > but why is the queue just 16 entries?
> > > > I explained the calculation in [1] about 16 entries.
> > > >
> > > > [1]
> > > >
> > > https://lore.kernel.org/netdev/PH0PR12MB54812EC7F4711C1EA4CAA119DC
> > > 419@
> > > > PH0PR12MB5481.namprd12.prod.outlook.com/
> > > >
> > > > > does the device not support indirect?
> > > > >
> > > > Yes, indirect feature bit is disabled on the device.
> > > 
> > > OK that explains it.
> > 
> > So can we proceed with v6 to contain 
> > (a) updated commit message and
> > (b) function name change you suggested to drop _fields suffix?
> 
> (c) replace mtu = 0 with sensibly not calling the function
> when mtu is unknown.
> 
> 
> And I'd like commit log to include results of perf testing
> - with indirect feature on
> - with mtu feature off
> just to make sure nothing breaks.

and if possible a larger ring. 1k?

> -- 
> MST