Re: -O0 kernel Re: High cpu temperature with 2.6.32, bisection showscommit 69d258 (fwd)
From: Dimitrios Apostolou
Date: Fri Jan 15 2010 - 15:37:38 EST
On Fri, 15 Jan 2010, Pavel Machek wrote:
BTW, how can I remove that irritating -O2 flag? I 'm used to compiling
with -O0 my debug builds in userland, because compilation is *many times*
faster. I should be really useful for bisections.
Actually, figuring out kernel flags for fastest kernel compilation
would be nice. Nice for bisect, and nice for slow machines. Zaurus
needs 4 hours to compile kernel, kohjinsha cca 1.5 hours.
-O0 may not fly, as inlining is needed... some tests are
I did some research too and this has been discussed again. Regarding
inlining and -O0 I understand that theoretically it should work, but
practically it doesn't. Here is an explanatory message from Andi Kleen:
http://lists.openwall.net/linux-kernel/2008/09/09/399
neccessary. Now that we support icc, gcc -O0 should be doable, too...
...ok, so I tried -O0.
-O2 compilation took 1250seconds, -O0 took 1167seconds and failed.
is there some fast compiler around that could be used?
Strange that -O0 was not faster. Compiling userland I'm sure I've seen
great speeds, and much less memory usage. Another compiler that is
infamous for its speed is TCC (Tiny C Compiler) but I haven't actually
used it, perhaps you want to try first. :-)
Dimitris
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/