From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
uclinux-dist-devel@blackfin.uclinux.org,
linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org,
linux-m32r@ml.linux-m32r.org, linux-m32r-ja@ml.linux-m32r.org,
linux-mips@linux-mips.org, linux-am33-list@redhat.com,
linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-s390@vger.kernel.org, linux-sh@vger.kernel.org,
sparclinux@vger.kernel.org, tglx@linutronix.de,
linux@arm.linux.org.uk, dhowells@redhat.com,
jejb@parisc-linux.org, linux390@de.ibm.com, x86@kernel.org,
cmetcalf@tilera.com, linux-m68k <linux-m68k@lists.linux-m68k.org>
Subject: Re: [PATCH RFC] Simplify the Linux kernel by reducing its state space
Date: Sat, 31 Mar 2012 09:54:01 -0700 [thread overview]
Message-ID: <20120331165401.GD2450@linux.vnet.ibm.com> (raw)
In-Reply-To: <CAMuHMdWTB+_AtqM6JixY=Oo_zmzX_dNxnivpARBYSbPJzp4t6A@mail.gmail.com>
On Sat, Mar 31, 2012 at 06:40:30PM +0200, Geert Uytterhoeven wrote:
> Hi Paul,
>=20
> On Sat, Mar 31, 2012 at 18:33, Paul E. McKenney
> <paulmck@linux.vnet.ibm.com> wrote:
> > Although there have been numerous complaints about the complexity o=
f
> > parallel programming (especially over the past 5-10 years), the pla=
in
> > truth is that the incremental complexity of parallel programming ov=
er
> > that of sequential programming is not as large as is commonly belie=
ved.
> > Despite that you might have heard, the mind-numbing complexity of m=
odern
> > computer systems is not due so much to there being multiple CPUs, b=
ut
> > rather to there being any CPUs at all. =A0In short, for the ultimat=
e in
> > computer-system simplicity, the optimal choice is NR_CPUS=3D0.
> >
> > This commit therefore limits kernel builds to zero CPUs. =A0This ch=
ange
> > has the beneficial side effect of rendering all kernel bugs harmles=
s.
> > Furthermore, this commit enables additional beneficial changes, for
> > example, the removal of those parts of the kernel that are not need=
ed
> > when there are zero CPUs.
> >
> > Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> > Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
> > ---
> >
> > =A0alpha/Kconfig =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 | =A0 11 +=
+++++-----
> > =A0arm/Kconfig =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 | =A0 =A0=
6 +++---
> > =A0blackfin/Kconfig =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0| =A0 =A03 +=
+-
> > =A0hexagon/Kconfig =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 | =A0 =A09 +=
++++----
> > =A0ia64/Kconfig =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0| =A0 =A0=
9 +++++----
> > =A0m32r/Kconfig =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0| =A0 10=
++++++----
> > =A0mips/Kconfig =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0| =A0 21=
+++++++++++----------
> > =A0mn10300/Kconfig =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 | =A0 =A03 +=
+-
> > =A0parisc/Kconfig =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0| =A0 =A06=
+++---
> > =A0powerpc/platforms/Kconfig.cputype | =A0 =A08 ++++----
> > =A0s390/Kconfig =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0| =A0 12=
+++++++-----
> > =A0sh/Kconfig =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0| =A0 =
11 ++++++-----
> > =A0sparc/Kconfig =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 | =A0 =A08=
++++----
> > =A0tile/Kconfig =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0| =A0 =A0=
9 +++++----
> > =A0x86/Kconfig =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 | =A0 16=
+++++++++-------
> > =A015 files changed, 78 insertions(+), 64 deletions(-)
>=20
> You forgot to fix half of the architectures, a.o. m68k?
I must confess that I fixed only the SMP-capable architectures.
I of course would welcome additions for UP-only architectures.
Thanx, Paul
next prev parent reply other threads:[~2012-03-31 16:54 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-31 16:33 [PATCH RFC] Simplify the Linux kernel by reducing its state space Paul E. McKenney
2012-03-31 16:40 ` Geert Uytterhoeven
2012-03-31 16:54 ` Paul E. McKenney [this message]
2012-03-31 19:57 ` Linas Vepstas
2012-03-31 20:14 ` Paul E. McKenney
2012-03-31 20:15 ` Linas Vepstas
2012-03-31 20:25 ` Randy Dunlap
2012-03-31 20:43 ` Paul E. McKenney
2012-03-31 21:00 ` Eric Dumazet
2012-03-31 21:21 ` Paul E. McKenney
2012-03-31 22:19 ` Lorenz Kolb
2012-03-31 22:34 ` Paul E. McKenney
2012-03-31 22:32 ` Russell King - ARM Linux
2012-04-01 1:22 ` Paul E. McKenney
2012-04-01 17:34 ` Thomas Gleixner
2012-04-01 18:12 ` Paul E. McKenney
2012-04-01 10:04 ` Borislav Petkov
2012-04-01 18:11 ` Paul E. McKenney
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