Re: [PATCH] ixgbe: do not include CRC in Tx byte count

[Stephen Hemminger <stephen-OTpzqLSitTUnbdJkjeBofR2eb7JE58TQ@public.gmane.org>]

On Mon, 23 Mar 2015 16:45:44 +0000
"Ananyev, Konstantin" <konstantin.ananyev-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> wrote:

> 
> 
> > -----Original Message-----
> > From: dev [mailto:dev-bounces-VfR2kkLFssw@public.gmane.org] On Behalf Of stephen-OTpzqLSitTUnbdJkjeBofR2eb7JE58TQ@public.gmane.org
> > Sent: Friday, January 23, 2015 6:24 AM
> > To: dev-VfR2kkLFssw@public.gmane.org
> > Cc: Stephen Hemminger
> > Subject: [dpdk-dev] [PATCH] ixgbe: do not include CRC in Tx byte count
> > 
> > From: Stephen Hemminger <shemming-43mecJUBy8ZBDgjK7y7TUQ@public.gmane.org>
> > 
> > The ixgbe driver was including CRC in the transmit packet byte
> > count, but not for packets received.
> > This was notice when forwarding and
> > the number of bytes received was greater than the number of bytes transmitted
> > for the same number of packets. Make the driver behave like other
> > virtual devices and not include CRC in byte count. Use the same queue
> > counters already computed and used for Rx.
> 
> About RX side stats - as I remember it depends to what value hw_stip_crc is set at configure().
> If hw_stip_crc==1, then, yes CRC bytes are not included into  QBRC value.
> I If hw_stip_crc==0, then CRC bytes are included into QBRC. 

That is an additional bug!
  * CRC should never be included in the byte count.
    This is not how Linux or other drivers report byte count.

  * the byte count must be symmetrical Rx == Tx

The Brocade router always set strip_crc to 1. So did not see the additional bug
of CRC being included in byte count.