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In-Reply-To: <YJAK1C1uLknYGYrH@mit.edu>
From:   Greg Stark <stark@mit.edu>
Date:   Tue, 4 May 2021 19:04:56 -0400
Message-ID: <CAM-w4HOJqDUyK9HXjtqD3K2ja1Wt=u2s5waQ1wqm7jHy0P5V-A@mail.gmail.com>
Subject: Re: Very slow clang kernel config ..
To:     "Theodore Ts'o" <tytso@mit.edu>
Cc:     "Maciej W. Rozycki" <macro@orcam.me.uk>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Tom Stellard <tstellar@redhat.com>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        clang-built-linux <clang-built-linux@googlegroups.com>,
        Fangrui Song <maskray@google.com>,
        Serge Guelton <sguelton@redhat.com>,
        Sylvestre Ledru <sylvestre@mozilla.com>
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On Mon, 3 May 2021 at 10:39, Theodore Ts'o <tytso@mit.edu> wrote:
>
> That was because memory was *incredibly* restrictive in those days.
> My first Linux server had one gig of memory, and so shared libraries
> provided a huge performance boost --- because otherwise systems would
> be swapping or paging their brains out.

(I assume you mean 1 megabyte?)
I have 16G and the way modern programs are written I'm still having
trouble avoiding swap thrashing...

This is always a foolish argument though. Regardless of the amount of
resources available we always want to use it as efficiently as
possible. The question is not whether we have more memory today than
before, but whether the time and power saved in reducing memory usage
(and memory bandwidth usage) is more or less than other resource costs
being traded off and whether that balance has changed.

> However, these days, many if not most developers aren't capable of the
> discpline needed to maintained the ABI stability needed for shared
> libraries to work well.

I would argue you have cause and effect reversed here. The reason
developers don't understand ABI (or even API) compatibility is
*because* they're used to people just static linking (or vendoring).
If people pushed back the world would be a better place.

-- 
greg