Re: [RFC] gcc feature request: Moving blocks into sections

From: Jason Baron
Date: Mon Aug 05 2013 - 16:06:55 EST


On 08/05/2013 02:39 PM, Steven Rostedt wrote:
On Mon, 2013-08-05 at 11:20 -0700, Linus Torvalds wrote:

Of course, it would be good to optimize static_key_false() itself -
right now those static key jumps are always five bytes, and while they
get nopped out, it would still be nice if there was some way to have
just a two-byte nop (turning into a short branch) *if* we can reach
another jump that way..For small functions that would be lovely. Oh
well.
I had patches that did exactly this:

https://lkml.org/lkml/2012/3/8/461

But it got dropped for some reason. I don't remember why. Maybe because
of the complexity?

-- Steve

Hi Steve,

I recall testing your patches and the text size increased unexpectedly. I believe I correctly accounted for changes to the text size *outside* of branch points. If you do re-visit the series that is one thing I'd like to double check/understand.

Thanks,

-Jason
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