[PATCH] cmdline: configure input buffer size

[Bruce Richardson]

On Wed, May 01, 2024 at 08:26:59AM +0300, Gregory Etelson wrote:
> DPDK defines cmdline input buffer size to 512 characters.
> That buffer size can be too small for long application input.
> For example, the following flow template API testpmd command is 444
> bytes long:
> ```
> flow queue 0 create 0 template_table 1000 \
>   pattern_template 0 actions_template 0 postpone no \
>   pattern eth / ipv4 / udp / end \
>   actions modify_field op set dst_type tag dst_level 0 dst_offset 0 \
>     src_type value src_value 0x31 width 32 /  \
>     modify_field op set dst_type ipv4_src src_type value \
>     src_value 10101010 width 32 / modify_field op add dst_type \
>     ipv4_ttl dst_level 0 dst_offset 0 src_type value \
>     src_value ff width 8 / count / jump group 100 / end
> ```
> 
> The patch introduces conditional `RDLINE_CUSTOM_BUF_SIZE` definition.
> Application can set custom cmdline size during DPDK configuration:
> 
> `meson setup ... -Dc_args='-DRDLINE_CUSTOM_BUF_SIZE=4096' ...`
> 
> Signed-off-by: Gregory Etelson <getelson at nvidia.com>
> ---
Basic question, what would be the impact of increasing the default from 512
to 1k or 2k? Do we get a large memory footprint increase, or is it just an
extra 1 or 2k of memory used?

/Bruce