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Date:   Wed, 24 Feb 2021 08:52:20 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     Christoph Hellwig <hch@lst.de>, Jessica Yu <jeyu@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        =?utf-8?B?77+8TWlyb3NsYXY=?= Benes <mbenes@suse.cz>,
        Emil Velikov <emil.l.velikov@gmail.com>
Subject: Re: [GIT PULL] Modules updates for v5.12
Message-ID: <20210224075220.GA546@lst.de>
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On Tue, Feb 23, 2021 at 12:07:39PM -0800, Linus Torvalds wrote:
> On Tue, Feb 23, 2021 at 12:03 PM Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> >
> > This is unacceptably slow. If that symbol trimming takes 30% of the
> > whole kernel build time, it needs to be fixed or removed.
> 
> I think I'm going to mark TRIM_UNUSED_KSYMS as "depends on BROKEN".
> There's no way I can accept that horrible overhead, and the rationale
> for that config option is questionable at best,

I think it is pretty useful for embedded setups.

BROKEN seems pretty strong for something that absolutely works as
intendended.  I guess to make you (and possibly others) not grumpy
we just need to ensure it doesn't get pulled in by allmodconfig.

So maybe just invert the symbol, default the KEEP_UNUSED_SYMBOL, and
add a message to the helptext explaining the slowdown?