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Stephen J. Turnbull
Sat, 24 Oct 2009 17:24:51 +0900
Dan Nicolaescu writes:
> > 1. XEmacs abandoned pure space years ago on the assumption that (bugs
> > aside) copy-on-write means that dumped text will be shared anyway.
> > Is that incorrect?
> Do you have generational GC? If not, all the data in the dumped image
> dumped image will be GCed every time, and that means lots of pages will
> get written to, so won't be shareable.
I don't think that's necessarily true. I'm not sure what the
mechanism for avoiding writes to dumped objects is in XEmacs; it might
be something like setting a "permanently marked object" bit and
putting them all in the set of GC roots at dumptime. (It's been a
while and I wasn't involved in that work at all.) And doesn't Emacs
keep its mark bits separately, being able to do that because objects
are allocated in arrays of same-sized blocks?
Re: BASE_PURESIZE, Dan Nicolaescu, 2009/10/23
Re: BASE_PURESIZE, Juanma Barranquero, 2009/10/23