Re: The Emacs master is much slower than the emacs-27 branch.

[Stephen Berman]

On Fri, 04 Dec 2020 14:53:32 +0100 Stephen Berman <stephen.berman@gmx.net> 
wrote:

> On Fri, 04 Dec 2020 15:28:06 +0200 Eli Zaretskii <eliz@gnu.org> wrote:
>
>>> From: Stephen Berman <stephen.berman@gmx.net>
>>> Cc: acm@muc.de,  emacs-devel@gnu.org
>>> Date: Fri, 04 Dec 2020 13:54:06 +0100
>>>
>>> >> As noted above, I build both master and emacs-27 with CFLAGS='-Og -g3'.
>>> >> Given that, is such a difference still expected?
>>> >
>>> > No.  But if you see this consistently, please produce and post the
>>> > profile of each of the versions, and let's take it from there.
>>>
>>> Since the builds I ran the benchmark on were about two weeks old, I
>>> updated both branches now, rebuilt and ran the benchmark again, and got
>>> the same results: ~21 seconds on master, ~61 seconds on emacs-27.
>>> Profiles attached.
>>
>> Thanks.  It looks like everything is just two to 3 times slower in
>> Emacs 28 on your system, which is definitely not my experience.
>         ^^
>         27
>
>> Are you sure all the Lisp files are byte-compiled?  What happens if
>> you "make bootstrap" in both branches, and then try again?
>
> I just rebuilt emacs-27 with "make bootstrap", reran the benchmark, and
> it took ~60 seconds, about a second faster than the previous
> non-bootstrapped build.  The profile is similar to the previous one from
> emacs-27, but I've attached for your perusal anyway.  I'll bootstrap
> master too and run the benchmark there again.

On freshly bootstrapped master the benchmark took the same time as
before, ~21 seconds, and the profile looks pretty much the same, so I
haven't attached it, but will send it if you want to see it.

Steve Berman