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* [dpdk-dev] [Bug 521] i40e: incorrect byte counters
@ 2020-08-07 15:36 bugzilla
  0 siblings, 0 replies; only message in thread
From: bugzilla @ 2020-08-07 15:36 UTC (permalink / raw)
  To: dev


            Bug ID: 521
           Summary: i40e: incorrect byte counters
           Product: DPDK
           Version: 18.11
          Hardware: All
                OS: All
            Status: UNCONFIRMED
          Severity: normal
          Priority: Normal
         Component: ethdev
          Assignee: dev@dpdk.org
          Reporter: iryzhov@nfware.com
  Target Milestone: ---

After running under 10G traffic over 3 days, the X710 card starts showing
incorrect RX/TX bytes statistics.

The problem seems to happen because of the following code in

        /* exclude CRC bytes */
        nes->rx_bytes -= (nes->rx_unicast + nes->rx_multicast +
                nes->rx_broadcast) * ETHER_CRC_LEN;

The rx_bytes counter in X710 cards is 48-bit long, so it takes around 3 days to
overflow. When it overflows, it becomes less than (rx_pkts * ETHER_CRC_LEN),
and the substruction makes it a negative number, or, to be more precise, a very
big positive number, as it's uint64_t.

For XL710 40G cards, it will take less than one day to face the issue.

You are receiving this mail because:
You are the assignee for the bug.

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2020-08-07 15:36 [dpdk-dev] [Bug 521] i40e: incorrect byte counters bugzilla

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