On Sun, Jun 24, 2007 at 05:58:46PM -0700, Arjan van de Ven wrote:
>
> > I wouldn't care if CONFIG_CC_OPTIMIZE_FOR_SIZE was hidden behind
> > CONFIG_EMBEDDED, but as long as it's available as a general purpose
> > option we have to consider it's performance.
>
> I think you are missing the point. You tell the kernel to
> OPTIMIZE_FOR_SIZE. *over performance*. Sure. Performance shouldn't be
> EXTREMELY pathetic, but it's not; and if it were, it's a problem with
> the gcc version you have (and if you are a distro, you can surely fix
> that)
My point is commit c45b4f1f1e149c023762ac4be166ead1818cefef
CC_OPTIMIZE_FOR_SIZE is currently known as an experimental feature to
improve the _performance_.
> > The interesting questions are:
> > Does -Os still sometimes generate faster code with gcc 4.2?
> > If yes, why?
>
> on a system level, size can help performance because you have more
> memory available for other things.
For a given gcc version, there's a finite number of differences between
-Os and -O2.
The interesting question is for which differences with gcc 4.2 we want
the -Os version in the kernel for best performance. This should then be
controllable through gcc options.
> It also reduces download size and
> gives you more space on the live CD....
That's a different point.
If you don't care about performance but care about size then -Os is
the best choice.
> if you want to make things bigger again, please do this OUTSIDE the
> "optimize for size" option. Because that TELLS you to go for size.
Agreed, but CONFIG_CC_OPTIMIZE_FOR_SIZE should again be under
CONFIG_EMBEDDED.
cu
Adrian
--
"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
