Re: [GIT PULL] Modules updates for v5.12

[Jessica Yu]

+++ Linus Torvalds [23/02/21 12:03 -0800]:
> On Tue, Feb 23, 2021 at 12:01 PM Christoph Hellwig <hch@xxxxxx> wrote:
> > Does your build now enable TRIM_UNUSED_KSYMS but previously didn't by
> > chance?
>
> Crossed emails.
>
> This is plain "make allmodconfig", so yes, now it will enable TRIM_UNUSED_KSYMS.
>
> This is unacceptably slow. If that symbol trimming takes 30% of the
> whole kernel build time, it needs to be fixed or removed.

[ Adding Masahiro to CC ]

It looks like CONFIG_TRIM_UNUSED_KSYMS had been hiding behind
CONFIG_UNUSED_SYMBOLS all this time, and once the EXPORT_UNUSED_SYMBOL
stuff was removed, it exposed that option to be selected by
allyesconfig. That option had previously caused build issues on
powerpc on linux-next, so I had temporarily marked that as BROKEN on
powerpc until Masahiro's fix landed in linux-next. I was not aware of
the additional build slowdown issue :/ In any case, Christoph's
suggestion to invert the option sounds reasonable, since the mips
defconfig selects it, it does not seem totally unused.