[dpdk-dev] [PATCH v3 1/2] eal: add additional info if core list too long

[Bruce Richardson]

On Tue, Sep 21, 2021 at 02:16:35PM +0100, David Hunt wrote:
>    On 21/9/2021 1:04 PM, David Hunt wrote:
> 
>      On 21/9/2021 12:57 PM, Bruce Richardson wrote:
> 
>      On Tue, Sep 21, 2021 at 12:50:14PM +0100, David Hunt wrote:
> 
>      If the user requests to use an lcore above 128 using -l,
>      the eal will exit with "EAL: invalid core list syntax" and
>      very little else useful information.
>      THis patch adds some extra information suggesting to use --lcores
>      so that physical cores above RTE_MAX_LCORE (default 128) can be
>      used. This is achieved by using the --lcores option by mapping
>      the logical cores in the application to physical cores.
>      There is no change in functionalty, just additional messages
>      suggesting how the --lcores option might be used for the supplied
>      list of lcores. For example, if "-l 12-16,130,132" is used, we
>      see the following additional output on the command line:
>      EAL: Error = One of the 7 cores provided exceeds RTE_MAX_LCORE (128)
>      EAL: Please use --lcores instead, e.g.
> 
>      Minor suggestion: it would be good to clarify how to use lcores and
>      what is
>      happening here in the example. Something like: "Please use --lcores
>      instead, to map lower lcore ids onto higher-numbered cores", could
>      help the
>      user understand better what is happening.
> 
>      Hi Bruce, how about:
>      EAL: Please use --lcores to map logical cores onto cores >
>      RTE_LCORE_MAX ,e.g. --lcores 0 at 12,1 at 13,2 at 14,3 at 15,4 at 16,5 at 130,6 at 132
>      Rgds,
>      Dave.
> 
>    I think this should do it, as it clarifies the mapping:
> 
>    EAL: lcore 130 >= RTE_MAX_LCORE (128)
>    EAL: lcore 132 >= RTE_MAX_LCORE (128)
>    EAL: to use high physical core ids , please use --lcores to map them to
>    lcore ids below RTE_LCORE_MAX, e.g. '--lcores
>    0 at 12,1 at 13,2 at 14,3 at 15,4 at 16,5 at 130,6 at 132'
> 
Text looks good to me.

Again minor nits: I think the continued lines should be indented,
and you should probably wrap immediately after the "e.g." rather than in
the middle of the parameter set.

/Bruce