[SLOF] [PATCH] Do not include the FCode evaluator by default anymore

Segher Boessenkool segher at kernel.crashing.org
Wed Aug 31 18:59:59 AEST 2016

On Wed, Aug 31, 2016 at 09:02:20AM +0200, Thomas Huth wrote:
> On 31.08.2016 07:44, Segher Boessenkool wrote:
> > On Wed, Aug 31, 2016 at 05:00:14AM +0200, Thomas Huth wrote:
> >> Commit 2fed5652819ad26627a8 ("Always include evaluator, move
> >> framebuffer token init to fbuffer.fs") made sure that the FCode
> >> evaluator is always included, during each boot cycle. The basic
> >> idea was that we would soon be starting to support PCI cards with
> >> FCode drivers on them. However, this has never happened, and so
> >> this change was in vain. The bad thing is now that the inclusion
> >> of the FCode evaluator also takes a lot of precious boot time,
> >> e.g. when running in QEMU TCG mode, it is more than a second.
> > 
> > Why is it so slow?
> The time is lost in token.fs. I think it's because it is using a lot of
> TICKs to set the behavior of the various tokens, and that seems to slow
> things down.

So name lookup is still too slow?  It is using a very simplistic cache
that sped it up >100x when I added it (was using a slow sim then, too),
but that cache is killed every time you change search order, etc.

I'll have a look at token.fs .


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