af73d78bd3
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@chromium.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/202003031814.4AEA3351@keescook
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.