From: Arnd Bergmann <arnd@arndb.de>
To: linuxppc-dev@ozlabs.org, balbir@linux.vnet.ibm.com
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] Fake NUMA emulation for PowerPC
Date: Fri, 7 Dec 2007 22:58:17 +0100 [thread overview]
Message-ID: <200712072258.19331.arnd@arndb.de> (raw)
In-Reply-To: <4759BE88.3020702@linux.vnet.ibm.com>
On Friday 07 December 2007, Balbir Singh wrote:
> Balbir Singh wrote:
> > Geert Uytterhoeven wrote:
> >> On Sat, 8 Dec 2007, Balbir Singh wrote:
> >>> +=A0=A0=A0if (strstr(p, "fake=3D"))
> >>> +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0cmdline =3D p + 5;=A0=A0=A0=A0=A0=
=A0=A0=A0/* 5 is faster than strlen("fake=3D") */
> >> Really? My gcc is smart enough to replace the `strlen("fake=3D")' by 5=
, even
> >> without -O.
> >>
> >=20
> > Thanks for pointing that out, but I am surprised that a compiler would
> > interpret library routines like strlen.
> >=20
>=20
> I just tested it and it turns out that you are right. I'll go hunt to
> see where gcc gets its magic powers from.
>=20
Even if it wasn't: Why the heck would you want to optimize this? The functi=
on
is run _once_ at boot time and the object code gets thrown away afterwards!
Arnd <><
WARNING: multiple messages have this Message-ID (diff)
From: Arnd Bergmann <arnd@arndb.de>
To: linuxppc-dev@ozlabs.org, balbir@linux.vnet.ibm.com
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] Fake NUMA emulation for PowerPC
Date: Fri, 7 Dec 2007 22:58:17 +0100 [thread overview]
Message-ID: <200712072258.19331.arnd@arndb.de> (raw)
In-Reply-To: <4759BE88.3020702@linux.vnet.ibm.com>
On Friday 07 December 2007, Balbir Singh wrote:
> Balbir Singh wrote:
> > Geert Uytterhoeven wrote:
> >> On Sat, 8 Dec 2007, Balbir Singh wrote:
> >>> + if (strstr(p, "fake="))
> >>> + cmdline = p + 5; /* 5 is faster than strlen("fake=") */
> >> Really? My gcc is smart enough to replace the `strlen("fake=")' by 5, even
> >> without -O.
> >>
> >
> > Thanks for pointing that out, but I am surprised that a compiler would
> > interpret library routines like strlen.
> >
>
> I just tested it and it turns out that you are right. I'll go hunt to
> see where gcc gets its magic powers from.
>
Even if it wasn't: Why the heck would you want to optimize this? The function
is run _once_ at boot time and the object code gets thrown away afterwards!
Arnd <><
next prev parent reply other threads:[~2007-12-07 21:58 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-07 21:14 [PATCH] Fake NUMA emulation for PowerPC Balbir Singh
2007-12-07 21:14 ` Balbir Singh
2007-12-07 21:28 ` Olof Johansson
2007-12-07 21:35 ` Balbir Singh
2007-12-07 21:55 ` Kumar Gala
2007-12-07 22:12 ` Balbir Singh
2007-12-07 22:15 ` Kumar Gala
2007-12-07 22:18 ` Balbir Singh
2007-12-07 23:10 ` David Rientjes
2007-12-07 23:10 ` David Rientjes
2007-12-08 4:22 ` Balbir Singh
2007-12-08 4:22 ` Balbir Singh
2007-12-09 13:16 ` Pavel Machek
2007-12-09 13:16 ` Pavel Machek
2007-12-09 13:20 ` Balbir Singh
2007-12-09 13:20 ` Balbir Singh
2007-12-07 23:06 ` David Rientjes
2007-12-07 23:06 ` David Rientjes
2007-12-07 21:30 ` Geert Uytterhoeven
2007-12-07 21:33 ` Dave Quigley
2007-12-07 21:35 ` Balbir Singh
2007-12-07 21:43 ` Balbir Singh
2007-12-07 21:58 ` Arnd Bergmann [this message]
2007-12-07 21:58 ` Arnd Bergmann
2007-12-07 22:03 ` Balbir Singh
2007-12-07 22:03 ` Balbir Singh
2007-12-07 22:01 ` Arnd Bergmann
2007-12-07 22:01 ` Arnd Bergmann
2007-12-07 22:22 ` Balbir Singh
2007-12-07 22:11 ` Nathan Lynch
2007-12-07 22:26 ` Balbir Singh
2007-12-07 23:11 ` David Rientjes
2007-12-07 23:11 ` David Rientjes
2007-12-08 4:32 ` Balbir Singh
2007-12-08 4:45 ` David Rientjes
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