Re: [PATCH RFC] Simplify the Linux kernel by reducing its state space

Hi Paul,

On Sat, Mar 31, 2012 at 18:33, Paul E. McKenney
[off-list ref] wrote:

Although there have been numerous complaints about the complexity of
parallel programming (especially over the past 5-10 years), the plain
truth is that the incremental complexity of parallel programming over
that of sequential programming is not as large as is commonly believed.
Despite that you might have heard, the mind-numbing complexity of modern
computer systems is not due so much to there being multiple CPUs, but
rather to there being any CPUs at all. =C2=A0In short, for the ultimate i=

n

computer-system simplicity, the optimal choice is NR_CPUS=3D0.

This commit therefore limits kernel builds to zero CPUs. =C2=A0This chang=

e

has the beneficial side effect of rendering all kernel bugs harmless.
Furthermore, this commit enables additional beneficial changes, for
example, the removal of those parts of the kernel that are not needed
when there are zero CPUs.

Signed-off-by: Paul E. McKenney <redacted>
Reviewed-by: Thomas Gleixner <redacted>
---

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=A0 =C2=A0 =C2=A0 =C2=A0| =C2=A0 =C2=A09 +++++----

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=A0 =C2=A0 =C2=A0| =C2=A0 =C2=A06 +++---

=C2=A0powerpc/platforms/Kconfig.cputype | =C2=A0 =C2=A08 ++++----
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=A0 =C2=A0 =C2=A0 | =C2=A0 =C2=A08 ++++----

=C2=A0tile/Kconfig =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=

=A0 =C2=A0 =C2=A0 =C2=A0| =C2=A0 =C2=A09 +++++----

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 =C2=A0 =C2=A0 =C2=A0 | =C2=A0 16 +++++++++-------

=C2=A015 files changed, 78 insertions(+), 64 deletions(-)

You forgot to fix half of the architectures, a.o. m68k?

Gr{oetje,eeting}s,

=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=
=A0 =C2=A0 Geert (still at GMT+2)

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

In personal conversations with technical people, I call myself a hacker. Bu=
t
when I'm talking to journalists I just say "programmer" or something like t=
hat.
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=
=A0 =C2=A0 =C2=A0 =C2=A0=C2=A0 =C2=A0=C2=A0 -- Linus Torvalds