Re: emacs rendering comparisson between emacs23 and emacs26.3

[Dmitry Gutov]

On 05.04.2020 21:23, Eli Zaretskii wrote:
> No, redisplay-dont-pause wasn't supposed to help when redisplay cannot
> keep up.  It is for the opposite use case: when redisplay is so slow
> it slows down processing of your commands, like typing, for example.
> You'd then set it to nil to speed up command processing, while giving
> up correct display at all times.

What's the difference between redisplay being slow and it being unable 
to "keep up"? I don't understand, sorry.

And in this case, IIUC, jit-lock is part of redisplay. And it's slow 
enough for this to be noticeable.