Re: [PATCH] ixgbevf - Prevent RX/TX statistics getting reset to zero

[Jeff Kirsher <tarbal@gmail.com>]

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On 07/12/2012 06:55 AM, Narendra_K@Dell.com wrote:
> Hello,
>
> [Apologies if you are receiving this message twice. I am resending the message, as I got message delivery failure note].
>
> While exploring SR-IOV on Intel 82599EB 10-Gigabit SFP+ adapter, I had the following observation.  I enabled two VFs by passing 'max_vfs=2' to ixgbe driver. One of the VFs was assigned to a guest.
> In the guest, the ifconfig and ip tools reported 'RX packets' and 'TX packets' as zero, after pinging to a remote host. Looking into it further, the commit 4197aa7bb81877ebb06e4f2cc1b5fea2da23a7bd implements 64 bit per ring statistics. It seemed like the 'total_bytes' and 'total_packets' of RX and TX ring were being reset to zero by the RX and TX interrupt handlers, resulting in the user space tools reporting zero RX and TX bytes. 
>
> The attached patch addresses the issue by preventing the resetting of RX and TX ring statistics to zero. The patch was taken against latest mainline 3.5-rc6 kernel.
>
> I tested the patch by pinging  from the guest OS to a remote host.
>
> ping -f <remote host> -c 10000
>
> The ip and ifcofig showed the statistics increased by 10000 packets.  
>
> # lspci | grep 82599
> 04:00.0 Ethernet controller: Intel Corporation 82599EB 10-Gigabit SFP+ Network Connection (rev 01)
> 04:00.1 Ethernet controller: Intel Corporation 82599EB 10-Gigabit SFP+ Network Connection (rev 01)
> 04:10.0 Ethernet controller: Intel Corporation 82599 Ethernet Controller Virtual Function (rev 01)
> 04:10.1 Ethernet controller: Intel Corporation 82599 Ethernet Controller Virtual Function (rev 01)
> 04:10.2 Ethernet controller: Intel Corporation 82599 Ethernet Controller Virtual Function (rev 01)
> 04:10.3 Ethernet controller: Intel Corporation 82599 Ethernet Controller Virtual Function (rev 01)
>
> # lspci -s 04:00.0 -n
> 04:00.0 0200: 8086:154d (rev 01)
> # lspci -s 04:10.0 -n
> 04:10.0 0200: 8086:10ed (rev 01) 
>
> Please let me know if additional details and logs are required. 
>
> With regards,
> Narendra K
>
>
>

Thanks, I will add the patch to my queue



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