From: "Gerd Möllmann" <gerd.moellmann@gmail.com>
To: Helmut Eller <eller.helmut@gmail.com>
Cc: "Gerd Möllmann" <gerd@gnu.org>,
"Stefan Monnier" <monnier@iro.umontreal.ca>,
"Pip Cet" <pipcet@protonmail.com>,
"Ihor Radchenko" <yantar92@posteo.net>,
emacs-devel@gnu.org
Subject: Re: MPS: marker-vector
Date: Tue, 06 Aug 2024 05:59:17 +0200 [thread overview]
Message-ID: <m24j7ywbca.fsf@pro2.fritz.box> (raw)
In-Reply-To: <87a5hqsq2l.fsf_-_@gmail.com> (Helmut Eller's message of "Mon, 05 Aug 2024 21:54:42 +0200")
Helmut Eller <eller.helmut@gmail.com> writes:
> What would you think about changing the marker-vector-with-free-list to
> a mundane growable array like in the patch below?
>
> The main motivation for this would that we could then iterate in
> reverse, or more precisely, in an order that is more like the order used
> for the linked-list-of-markers. This is relevant for the heuristic in
> buf_charpos_to_bytepos that creates a temporary marker; it works better
> if those temporary markers are visited first.
>
> Using Stefan's elb-bytechar benchmark, I get for the
> linked-list-of-markers:
>
> | test || tot avg (s) | tot avg err (s) |
> |------------------------++-------------+-----------------|
> | bytechar || 11.80 | 0.00 |
> | bytechar-100k || 11.85 | 0.00 |
> | bytechar-100k-nolookup || 9.19 | 0.00 |
> | bytechar-100k-random || 16.73 | 0.02 |
> | bytechar-100k-rev || 11.86 | 0.00 |
> | bytechar-10k-random || 12.36 | 0.01 |
> | bytechar-1k-random || 11.93 | 0.00 |
> | bytechar-nolookup || 9.15 | 0.00 |
> |------------------------++-------------+-----------------|
> | total || 94.88 | 0.02 |
>
> for the vector-with-free-list:
>
> | test || tot avg (s) | tot avg err (s) |
> |------------------------++-------------+-----------------|
> | bytechar || 11.63 | 0.01 |
> | bytechar-100k || 11.91 | 0.37 |
> | bytechar-100k-nolookup || 8.80 | 0.01 |
> | bytechar-100k-random || 248.07 | 3.84 |
> | bytechar-100k-rev || 11.71 | 0.02 |
> | bytechar-10k-random || 35.24 | 0.53 |
> | bytechar-1k-random || 14.01 | 0.06 |
> | bytechar-nolookup || 8.69 | 0.13 |
> |------------------------++-------------+-----------------|
> | total || 350.06 | 3.89 |
>
> and for the growable array:
>
> | test || tot avg (s) | tot avg err (s) |
> |------------------------++-------------+-----------------|
> | bytechar || 11.34 | 0.08 |
> | bytechar-100k || 11.59 | 0.47 |
> | bytechar-100k-nolookup || 8.78 | 0.12 |
> | bytechar-100k-random || 16.17 | 0.33 |
> | bytechar-100k-rev || 11.31 | 0.03 |
> | bytechar-10k-random || 11.76 | 0.01 |
> | bytechar-1k-random || 11.34 | 0.08 |
> | bytechar-nolookup || 8.70 | 0.09 |
> |------------------------++-------------+-----------------|
> | total || 91.00 | 0.61 |
>
> So the results of the growable array and the linked-list-of-markers
> would be closer. A downside of the growable array is that it needs a
> bit of extra code for the dumper. I didn't try to port the gap array
> code, because it seems like it would require many more changes and would
> make it even harder to merge with master.
Hm, can't say much about the benchmark, I'm afraid. I've been
successfully ignoring this topic so far :-). I don't even know what the
impact of these numbers in a larger context is.
That said, if you find it important, I trust that, so no objections from
me.
Technically speaking, from reading the diff, I think it's okay. The only
thing I'm wondering about is the compacting of the vector while
iterating over it. I can't put my finger on it, but Is that always safe?
(And I don't know if one can call mps_scan_area without MPS_SCAN_BEGIN/END.)
next prev parent reply other threads:[~2024-08-06 3:59 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-04 4:59 Markers in a gap array Stefan Monnier
2024-07-04 10:24 ` Ihor Radchenko
2024-07-04 13:16 ` Stefan Monnier
2024-07-04 14:30 ` Ihor Radchenko
2024-07-04 20:11 ` Stefan Monnier
2024-07-04 20:34 ` Pip Cet
2024-07-04 20:42 ` Stefan Monnier
2024-07-17 16:48 ` Helmut Eller
2024-07-18 20:46 ` Stefan Monnier
2024-07-26 19:48 ` Helmut Eller
2024-08-05 19:54 ` MPS: marker-vector (was: Markers in a gap array) Helmut Eller
2024-08-05 21:14 ` MPS: marker-vector Pip Cet
2024-08-06 6:28 ` Helmut Eller
2024-08-06 6:51 ` Gerd Möllmann
2024-08-06 14:36 ` Pip Cet
2024-08-06 16:15 ` Helmut Eller
2024-08-06 3:59 ` Gerd Möllmann [this message]
2024-08-06 6:02 ` Helmut Eller
2024-07-04 22:24 ` Markers in a gap array Stefan Monnier
2024-07-07 12:31 ` Ihor Radchenko
2024-07-07 13:09 ` Konstantin Kharlamov
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