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From: Stephen Hemminger <stephen@networkplumber.org>
To: Hyong Youb Kim <hyonkim@cisco.com>
Cc: John Daley <johndale@cisco.com>, ferruh.yigit@intel.com, dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v3 08/10] doc: describe Rx bytes counter behavior for enic
Date: Thu, 8 Mar 2018 17:48:27 -0800	[thread overview]
Message-ID: <20180308174827.68ee4683@xeon-e3> (raw)
In-Reply-To: <20180309005253.GA19460@HYONKIM-FTCPE.cisco.com>

On Fri, 9 Mar 2018 09:52:54 +0900
Hyong Youb Kim <hyonkim@cisco.com> wrote:

> On Thu, Mar 08, 2018 at 02:14:27PM -0800, Stephen Hemminger wrote:
> > On Wed,  7 Mar 2018 18:47:00 -0800
> > John Daley <johndale@cisco.com> wrote:
> >   
> > >      'catch-all' filters should be added last.
> > >  
> > > +- **Statistics**
> > > +
> > > +  - ``rx_good_bytes`` (ibytes) always includes VLAN header (4B) and CRC bytes (4B).
> > > +  - When the NIC drops a packet because the Rx queue has no free buffers,
> > > +    ``rx_good_bytes`` still increments by 4B if the packet is not VLAN tagged or
> > > +    VLAN stripping is disabled, or by 8B if the packet is VLAN tagged and stripping
> > > +    is enabled.  
> > 
> > All drivers must provide consistent statistics!
> > That means do NOT include CRC in the rx byte counts.
> > Yes, several drivers in DPDK are already broken for this.
> > 
> > Otherwise there are cases like packets being forwarded from HW NIC to virtio and the counts
> > differ and customers think data is lots.  
> 
> Thanks for sharing this specific use case issue.
> 
> We are aware that our current counters are non-standard. Newer 100G
> hardware models have fixed the problem (i.e. no CRC bytes, no
> incrementing of bytes when no buffers). We plan to update the doc
> again when we add these newer models to the supported hardware list.
> 
> As for older models, we will see if we can fix up stats in software..
> 
> -Hyong

Don't worry some of the Intel drivers are buggy last I checked.
Also make sure that when forwarding that bytes transmitted == bytes received.
There were some drivers adding CRC on the receive but no on transmit.

It maybe true that you want to count CRC if the CRC stripping flag is not set.

  reply	other threads:[~2018-03-09  1:48 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-24 19:17 [dpdk-dev] [PATCH] net/enic: remove 'extern' in .h file function declarations John Daley
2018-02-24 19:17 ` [dpdk-dev] [PATCH] net/enic: allow the user to change RSS settings John Daley
2018-02-24 19:17 ` [dpdk-dev] [PATCH] net/enic: heed the requested max Rx packet size John Daley
2018-02-24 19:17 ` [dpdk-dev] [PATCH] net/enic: remove the VLAN filter handler John Daley
2018-02-24 19:17 ` [dpdk-dev] [PATCH] net/enic: add Rx/Tx queue configuration getters John Daley
2018-02-24 19:17 ` [dpdk-dev] [PATCH] net/enic: allocate stats DMA buffer upfront during probe John Daley
2018-02-24 19:17 ` [dpdk-dev] [PATCH] net/enic: support Rx queue interrupts John Daley
2018-02-24 19:17 ` [dpdk-dev] [PATCH] doc: describe Rx bytes counter behavior for enic John Daley
2018-02-24 19:17 ` [dpdk-dev] [PATCH] net/enic: use memcpy to avoid strict aliasing warnings John Daley
2018-02-24 19:17 ` [dpdk-dev] [PATCH] net/enic: support for meson John Daley
2018-03-06  1:46   ` [dpdk-dev] [PATCH v2 00/10] enic patchset John Daley
2018-03-06  1:46     ` [dpdk-dev] [PATCH v2 01/10] net/enic: remove 'extern' in .h file function declarations John Daley
2018-03-08  2:46       ` [dpdk-dev] [PATCH v3 00/10] enic PMD patchset John Daley
2018-03-08  2:46         ` [dpdk-dev] [PATCH v3 01/10] net/enic: remove 'extern' in .h file function declarations John Daley
2018-03-08  2:46         ` [dpdk-dev] [PATCH v3 02/10] net/enic: allow the user to change RSS settings John Daley
2018-03-09 14:35           ` Ferruh Yigit
2018-03-08  2:46         ` [dpdk-dev] [PATCH v3 03/10] net/enic: heed the requested max Rx packet size John Daley
2018-03-09 15:03           ` Ferruh Yigit
2018-03-09 15:51             ` Ananyev, Konstantin
2018-03-09 15:57               ` Ferruh Yigit
2018-03-10  0:37                 ` Hyong Youb Kim
2018-03-08  2:46         ` [dpdk-dev] [PATCH v3 04/10] net/enic: remove the VLAN filter handler John Daley
2018-03-08  2:46         ` [dpdk-dev] [PATCH v3 05/10] net/enic: add Rx/Tx queue configuration getters John Daley
2018-03-08  2:46         ` [dpdk-dev] [PATCH v3 06/10] net/enic: allocate stats DMA buffer upfront during probe John Daley
2018-03-08  2:46         ` [dpdk-dev] [PATCH v3 07/10] net/enic: support Rx queue interrupts John Daley
2018-03-08  2:47         ` [dpdk-dev] [PATCH v3 08/10] doc: describe Rx bytes counter behavior for enic John Daley
2018-03-08 22:14           ` Stephen Hemminger
2018-03-09  0:52             ` Hyong Youb Kim
2018-03-09  1:48               ` Stephen Hemminger [this message]
2018-03-08  2:47         ` [dpdk-dev] [PATCH v3 09/10] net/enic: use memcpy to avoid strict aliasing warnings John Daley
2018-03-08  2:47         ` [dpdk-dev] [PATCH v3 10/10] net/enic: support for meson John Daley
2018-03-08  9:49           ` Bruce Richardson
2018-03-09 16:00         ` [dpdk-dev] [PATCH v3 00/10] enic PMD patchset Ferruh Yigit
2018-03-10  0:49           ` Hyong Youb Kim
2018-03-06  1:46     ` [dpdk-dev] [PATCH v2 02/10] net/enic: allow the user to change RSS settings John Daley
2018-03-06  1:46     ` [dpdk-dev] [PATCH v2 03/10] net/enic: heed the requested max Rx packet size John Daley
2018-03-06  1:46     ` [dpdk-dev] [PATCH v2 04/10] net/enic: remove the VLAN filter handler John Daley
2018-03-06  1:46     ` [dpdk-dev] [PATCH v2 05/10] net/enic: add Rx/Tx queue configuration getters John Daley
2018-03-06  1:46     ` [dpdk-dev] [PATCH v2 06/10] net/enic: allocate stats DMA buffer upfront during probe John Daley
2018-03-06  1:46     ` [dpdk-dev] [PATCH v2 07/10] net/enic: support Rx queue interrupts John Daley
2018-03-06  1:46     ` [dpdk-dev] [PATCH v2 08/10] doc: describe Rx bytes counter behavior for enic John Daley
2018-03-06  1:46     ` [dpdk-dev] [PATCH v2 09/10] net/enic: use memcpy to avoid strict aliasing warnings John Daley
2018-03-06  1:46     ` [dpdk-dev] [PATCH v2 10/10] net/enic: support for meson John Daley

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