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Question about stats shown by ethtool on PFE

Question asked by David Dailey on Jan 22, 2019
Latest reply on Feb 4, 2019 by Pavel Chubakov

Hello,

 

Please help me understand a strange behavior with the ethtool stats from the LS1012A.  On our board with a previous 4.1.8 kernel from the Qoriq SDK (4.1.8) with pfe binary version pfe_ls1012a_00_1-dirty, we see the IEEE_rx_drop statistic count increase for eth0, but there is no noticeable performance change (as though they are not really errored and still going through the Linux stack).  With the latest LSDK kernel version 4.14.83 from CodeAurora and pfe binary pfe_ls1012a_slowpath_06, we see the same IEEE_rx_drop statistic increment, but the performance is suffering as though there really are packet losses.  There are no other ethtool error stats that count, like RX CRC errors.  We also do not see this error count when connected to various other switches (like desktop switches), just one particular vendor switch of the various ones we have in our lab.

 

Can you please explain what IEEE_rx_drop means on the PFE, and why the effects may differ between pfe binary/kernel versions?  If errored frames, it seems some other stats like CRC errors should also show.  Is there some way to make the current behavior the same as on the older kernel?

 

Thank you,

Dave

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