Re: [PATCH bpf-next v2] kbuild: Remove debug info from kallsyms linking

[Daniel Borkmann]

On 3/4/20 3:18 AM, Kees Cook wrote:
> When CONFIG_DEBUG_INFO is enabled, the two kallsyms linking steps spend
> time collecting and writing the dwarf sections to the temporary output
> files. kallsyms does not need this information, and leaving it off
> halves their linking time. This is especially noticeable without
> CONFIG_DEBUG_INFO_REDUCED. The BTF linking stage, however, does still
> need those details.
>
> Refactor the BTF and kallsyms generation stages slightly for more
> regularized temporary names. Skip debug during kallsyms links.
> Additionally move "info BTF" to the correct place since commit
> 8959e39272d6 ("kbuild: Parameterize kallsyms generation and correct
> reporting"), which added "info LD ..." to vmlinux_link calls.
>
> For a full debug info build with BTF, my link time goes from 1m06s to
> 0m54s, saving about 12 seconds, or 18%.
>
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> Acked-by: Andrii Nakryiko <andriin@xxxxxx>

Applied, thanks!