Re: [Patch 4/4] Tell GCC 4.1 to move unlikely() code to a separate section

[Andi Kleen]

On Monday 27 February 2006 16:31, Arjan van de Ven wrote:
> This patch is more controversial I assume; it offers the option 
> to use the gcc 4.1 option to move unlikely() code to a separate section.
> On the con side, this means that longer byte sequences are needed to jump
> to this code, on the Pro side it means that the unlikely() code isn't sharing
> icache cachelines and tlbs anymore.

I don't think this will do anything because the default Makefile
still has

CFLAGS += -fno-reorder-blocks 

That was me because it made assembly debugging much easier. I would be willing
to reconsider this if you can give me some hard data just from this change:
- benchmark changes
- .text size increase

Also I don't like it being an separate CONFIG options. We already have too many
obscure ones. Either it should be on by default or not there at all.

-Andi
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