How To Bypass Local Cache (Disable tx-nocache-copy)

Version 3

    "tx-nocache-copy" is a feature which bypasses local cache and writes user-space data directly into memory. 

    New kernels have this feature disabled by default, while on it comes enabled on some Linux distributions.

    It is recommended to disable this feature, as it can harm performance.

     

    References

     

    Configuration

    To disable tx-nocache-copy, run:

    # ethtool -K eth1 tx-nocache-copy off

    To enable tx-nocache-copy, run:

    # ethtool -K eth1 tx-nocache-copy on

    To view current configuration, run:

    # ethtool --show-offload eth1 | grep tx-nocache-copy

    tx-nocache-copy: off