Re: [patch 00/2] improve .text size on gcc 4.0 and newer compilers

Arjan van de Ven
2006-01-05T12:22:41Z

> What would be nice to do is pack all the frequently used code together
> in close proximity. Would probably have much larger effects with
> userspace code, esp where we touch disk (which is more page-size
> granularity), but is probably worth doing with kernel code too (where
> AFAICS we'd only get cacheline granular).

in the kernel we could make a .text.rare section for functions, which we
could annotate with __rare.
The other way around, __fastpath or whatever is a bad idea, everyone
will consider all of their own functions as such (just like inline ;)...
go-fast-stripes all the way :-(

obvious candidates for __rare are
* pm suspend/resume functions
* error handling functions
* initialization stuff (including mount time stuff for filesystems,
and hardware setup for drivers)

I wonder if gcc can be convinced to put all unlikely() code sections
into a .text.rare as well, that'd be really cool.