Re: Larger GC thresholds for non-interactive Emacs

[Lars Ingebrigtsen]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> Here are the results of a similar test where I tried to avoid the above
> problem by also removing src/boostrap-emacs (and I also rm'd
> lisp/loaddefs.el for good measure tho it was probably not a great idea),
> and I used
>
>     BYTE_COMPILE_EXTRA_FLAGS="--eval '(setq gc-cons-percentage $FOO)'":
>
> make -j24 FOO=0.1    1338.52s user 60.95s system 1256% cpu 1:51.42 total

[...]

> make -j24 FOO=2.0     678.14s user 68.64s system 1044% cpu 1:11.52 total

Nice!

> This suggests that for batch jobs maybe we should bump up
> `gc-cons-percentage` from 0.1 to something like 1.0 or 2.0.

Yup.  But do you mean in general?  I.e., -batch would set that variable
to 2.0?  Would there be any likely major repercussions -- i.e., jobs
that used to run fine would run out of memory?

As a quick test, I added a (setq gc-cons-percentage 2.0) to startup.el
here, and a

git clean -dfx
time make -j32

went from 1m29s to 1m4s.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no