Hi Olof,

On Fri, Oct 1, 2021 at 7:36 AM Olof Johansson [off-list ref] wrote:

A much more valuable approach would be to work towards being able to
free up memory by un-probed drivers at the end of boot. That would
possibly benefit all platforms on all architectures.

We used to have such a functionality in arch/ppc (not arch/powerpc!),
where code/data could be tagged __prep, __chrp, or __pmac, to put it
in a special section, and to be freed with initdata when unused.  It
was removed in v2.6.15[1], as the savings weren't worth the hassle.
In a more fragmented space like arm the memory lost due to alignment
of the sections would be even more substantial.

Another problem is to know when is the end of the boot, especially
with deferred probing.

[1] 6c45ab992e4299c8 ("[PATCH] powerpc: Remove section free() and
linker script bits")

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds