Re: Time to merge scratch/correct-warning-pos into master, perhaps?

[Alan Mackenzie]

Hello, Eli.

On Sun, Feb 06, 2022 at 13:56:34 +0200, Eli Zaretskii wrote:
> > Date: Sun, 6 Feb 2022 11:50:02 +0000
> > Cc: gregory@heytings.org, monnier@iro.umontreal.ca, mattiase@acm.org,
> >   larsi@gnus.org, emacs-devel@gnu.org
> > From: Alan Mackenzie <acm@muc.de>

> > > So that would mean the slowdown of EQ is due to the cases where the
> > > objects are not-EQ?

> > Yes.

> > > Where are the numbers that show how much slower is the current EQ, for
> > > the case of EQ and not-EQ objects?

> > We don't have any such numbers.  Is it even possible to measure this?  On
> > earlier processors, we could have just counted up processor cycles used
> > for each instruction, but not any more.

> Yes, it's possible: use perf.

I've installed the user side part of perf on my machine.  On reading the
tutorial (which is very difficult), it seems perf acts like a super
accurate benchmarking program, which measures program runs.

Maybe I misunderstand what you meant - but I can't see how perf is able
to report the cycles, etc., taken by a single execution of an instance of
EQ.

What exactly do we want to measure, here?

-- 
Alan Mackenzie (Nuremberg, Germany).