Re: [PATCH] powerpc: Add gpr1 and fpu save/restore functions

[Segher Boessenkool <segher@kernel.crashing.org>]

On Mon, Feb 12, 2024 at 11:46:19AM -0600, Timothy Pearson wrote:
> Interesting, that make sense.
> 
> How should we proceed from the current situation?  Bringing in libgcc seems
> like a fairly invasive change,

I have done it for *all* architectures some ten years ago.  Never found
any problem.

> should we merge this to fix the current bug
> (cannot build ppc64 kernel in size-optimized mode) and start discussion on
> bringing in libgcc as the long-term fix across multiple architectures?
> 
> My goal here is to not have to carry a downstream patch in perpetuity for
> our embedded Linux firmware, which needs to be compiled in size-optimized
> mode due to hardware Flash limitations.

There are better options than -Os, fwiw.  Some --param's give smaller
*and* faster kernels.  What exactly is best is heavily arch-dependent
though (as well as dependent on the application code, the kernel code in
this case) :-(


Segher