Re: emacs rendering comparisson between emacs23 and emacs26.3

[martin rudalics]

>> I cannot nearly simulate the problem using a simple loop that steadily
>> invokes say (forward-line 50) followed by a (sit-for 0).  50 such
>> invocations take 16.7 seconds here, 22.7 with (forward-line -50).
>
> 16s in one case a "10 seconds freeze": it sounds to me like you *do*
> reproduce the problem.

Not really.  In the 16s case redisplay kicks in and displays the buffer
250 times.  In the 10s case redisplay stops after five times.

> The only difference is that with actual keyboard input pending the
> redisplay is partly prevented which is what you perceive as "freeze",
> but the real problem is the time it takes.

What does get fontified when redisplay freezes?

martin