Re: cperl + isearch + font-lock-multiline sometimes very slow

[Chong Yidong]

Chong Yidong <address@hidden> writes:

>> (setq font-lock-multiline t)
>> (require 'printing "printing" 'no-error)
>> (fset 'perl-mode 'cperl-mode)
>>
>> With these 3 lines I can still observe the problem.
>> 1. Start emacs with .emacs containing the 3 lines above
>> 2. load a Perl file (not too small), I use perl5db.pl from the Perl 
>> distribution
>> 3. Watch emacs CPU usage
>>
>> After approximaetly 25 seconds, the CPU usage climbs for nearly 3 minutes
>> to 55% and emacs behaves very sluggish. Afterwards emacs behaves normal.
>> No need for isearch, that was obviously a misinterpretation.
>
> I still can't reproduce this, using the above .emacs file and
> perl5db.pl.

To be precise, I save the above three lines into foo.el, and do

 emacs -Q -l foo.el /usr/share/perl/5.8/perl5db.pl

After waiting several minutes and watching with `top', I observe that
Emacs' CPU usage never exceeds 4.5% (which is normal for jit stealth
fontification), and there is no sluggishness either in Emacs or other
programs.  Maybe the scheduler in Solaris (which I noticed you are
using) behaves funny.