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Re: Preview: portable dumper
From: |
Eli Zaretskii |
Subject: |
Re: Preview: portable dumper |
Date: |
Tue, 29 Nov 2016 21:02:56 +0200 |
> From: Daniel Colascione <address@hidden>
> Cc: John Wiegley <address@hidden>, address@hidden, address@hidden,
> address@hidden
> Date: Tue, 29 Nov 2016 10:49:10 -0800
>
> > Any memory dumper will always be more efficient than loading .elc.
> [...]
> Because you can't possible get away, in the ELC approach, from:
>
> 1) reading every damn byte of the file, and
> 2) allocating memory for every object you read.
>
> Efficiency is always going to be at least linear in the size of the
> "elc dump" --- super-linear complexity if you want read-circle.
>
> A memory dump is linear only in the amount of data you actually
> access. Plus, there's no serialization or deserialization overhead. A
> memory dump is also inherently gentler on the underlying system, since
> we can use many of the pages unmodified (which makes them shareable and
> trivially swappable), while every damn byte of the Emacs heap after
> loading ELC files will be process-private dirty storage.
Like I said: any memory dumper will always be faster. But having less
functionality coded in non-trivial C is IMO an important goal, one we
have been pursuing for quite some time, and for a good reason.
Although it should be clear that any adequate C implementation will
always be faster than an equivalent Lisp implementation.
> I do not think the portable dumper is something that's so complex as to
> not be worth the performance
It's complex. I have read the patch. I do know my way in the Emacs
internals.
> especially since any lread implementation that's even close to being
> acceptably fast is going to be very complex in its own right.
Even if we accept your opinion on the necessity for changes in lread
(and I don't think I agree), that is a one-off job.
- Re: Preview: portable dumper, (continued)
- Re: Preview: portable dumper, Eli Zaretskii, 2016/11/29
- Re: Preview: portable dumper, Daniel Colascione, 2016/11/29
- Re: Preview: portable dumper, Eli Zaretskii, 2016/11/29
- Re: Preview: portable dumper, John Wiegley, 2016/11/29
- Re: Preview: portable dumper, Eli Zaretskii, 2016/11/29
- Re: Preview: portable dumper, Daniel Colascione, 2016/11/29
- Re: Preview: portable dumper,
Eli Zaretskii <=
- Re: Preview: portable dumper, John Wiegley, 2016/11/28
- Re: Preview: portable dumper, Burton Samograd, 2016/11/28
- Re: Preview: portable dumper, Eli Zaretskii, 2016/11/28
Re: Preview: portable dumper, Paul Eggert, 2016/11/28
- Re: Preview: portable dumper, Eli Zaretskii, 2016/11/28
- Re: Preview: portable dumper, John Wiegley, 2016/11/28
- Re: Preview: portable dumper, Eli Zaretskii, 2016/11/28
- Re: Preview: portable dumper, Daniel Colascione, 2016/11/28
- Re: Preview: portable dumper, John Wiegley, 2016/11/28
- Re: Preview: portable dumper, Eli Zaretskii, 2016/11/29