Set inhibit-compacting-font-caches non-nil on MS-Windows

Set inhibit-compacting-font-caches non-nil on MS-Windows

[Eli Zaretskii]

I think we should make this variable non-nil by default on
MS-Windows.

There are quite a few bug reports in the bug DB which all complain
about slow redisplay on MS-Windows, and were resolved by setting this
variable non-nil.  So it sounds like on MS-Windows the compacting of
the font caches is not a good idea (the original code was written to
fix a problem observed on X).

Any objections/comments?

Re: Set inhibit-compacting-font-caches non-nil on MS-Windows

[Eli Zaretskii]

> Date: Sat, 03 Aug 2019 15:20:54 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> 
> I think we should make this variable non-nil by default on
> MS-Windows.
> 
> There are quite a few bug reports in the bug DB which all complain
> about slow redisplay on MS-Windows, and were resolved by setting this
> variable non-nil.  So it sounds like on MS-Windows the compacting of
> the font caches is not a good idea (the original code was written to
> fix a problem observed on X).
> 
> Any objections/comments?

No objections, so I've now made such a change on master.

Re: Set inhibit-compacting-font-caches non-nil on MS-Windows

[Stefan Kangas]

Eli Zaretskii <eliz@gnu.org> writes:

> I think we should make this variable non-nil by default on
> MS-Windows.
>
> There are quite a few bug reports in the bug DB which all complain
> about slow redisplay on MS-Windows, and were resolved by setting this
> variable non-nil.  So it sounds like on MS-Windows the compacting of
> the font caches is not a good idea (the original code was written to
> fix a problem observed on X).
>
> Any objections/comments?

Since there have been no objections, perhaps it's time to do this change?

Best regards,
Stefan Kangas

Re: Set inhibit-compacting-font-caches non-nil on MS-Windows

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Fri, 13 Sep 2019 14:14:31 +0200
> Cc: emacs-devel@gnu.org
> 
> Since there have been no objections, perhaps it's time to do this change?

Already done in f34f49f35, and announced in
https://lists.gnu.org/archive/html/emacs-devel/2019-09/msg00177.html.

Thanks.

RE: Set inhibit-compacting-font-caches non-nil on MS-Windows

[Drew Adams]

> I think we should make this variable non-nil by default on
> MS-Windows.
> 
> There are quite a few bug reports in the bug DB which all complain
> about slow redisplay on MS-Windows, and were resolved by setting this
> variable non-nil.  So it sounds like on MS-Windows the compacting of
> the font caches is not a good idea (the original code was written to
> fix a problem observed on X).

+1.  Bugs #30539 and #32159, for instance.

Re: Set inhibit-compacting-font-caches non-nil on MS-Windows

[Andy Moreton]

On Sat 03 Aug 2019, Drew Adams wrote:

>> I think we should make this variable non-nil by default on
>> MS-Windows.
>> 
>> There are quite a few bug reports in the bug DB which all complain
>> about slow redisplay on MS-Windows, and were resolved by setting this
>> variable non-nil.  So it sounds like on MS-Windows the compacting of
>> the font caches is not a good idea (the original code was written to
>> fix a problem observed on X).
>
> +1.  Bugs #30539 and #32159, for instance.

I don't see this problem in my usual setup on Windows, probably because
I have configured the fonts used in `fontset-default', resulting in
shorter searches for suitable fonts.

As Eli pointed out in a previous discussion, configuring the default
fontset to contain the right fonts for multiple versions of Windows is a
fair amount of work, and would require ongoing maintenance.

Given that, setting inhibit-compacting-font-caches non-nil on Windows
seems a pragmatic workaround.

    AndyM