Re: RE: RE: [virtio-dev] RE: RE: RE: RE: [PATCH v16] virtio-net: support device stats

[Xuan Zhuo <xuanzhuo@linux.alibaba.com>]

On Tue, 5 Sep 2023 03:31:41 +0000, Parav Pandit <parav@nvidia.com> wrote:
>
>
> > From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > Sent: Tuesday, September 5, 2023 8:26 AM
>
> > > Sure, it can avoid segmentation, but not at the cost of skipping mtu check.
> > > For example, sender sends skb with gso with each segment of 9K, and receiver
> > has mtu of 1500, same skb without segmentation is not good.
> > > Because gso_size should be same as 1500 to match the mtu.
> >
> > First, for me, I think the size of the each buffer specified by the desc is irrelated
> > to the gso_size.
> >
> > And the receiver can set the gso_size to match the MTU.
> >
> > So the sender can send a gso packet with any segments, any gso_size.
> > For the receiver, it receives a big packet, it copys to the driver with multple
> > buffers, and sets the right gso_size.
> >
> > Is that right?
>
> Right.
> By definition of GSO it is segmented.
> Soi counters should be for the segmented.
> And for special case of "Note", there should be separate counter to indicate GSO was requested_but_not_done.


I agree. So the new version should be:

+\begin{description}
+    \item [tx_gso_packets]
+        The number of the GSO packets sent by the device.
+
+    \item [tx_gso_bytes]
+        The bytes of the GSO packets sent by the device.
+
+    \item [tx_gso_segments]
+        The number of segments cutted from GSO packets.
+
+    \item [tx_gso_segments_bytes]
+        The bytes of segments cutted from GSO packets.

+    \item [tx_gso_packets_nocut]
+        The number of the GSO packets which are not cut into segments.
+
+    \item [tx_gso_bytes_nocut]
+        The bytes of the GSO packets which are not cut into segments.
+
+\end{description}


Thanks.