bug#18522: 24.4.50; mapcar is very slow

[Lars Ingebrigtsen]

Peter Münster <pmlists@free.fr> writes:

>> (benchmark-run 1
>>  (dotimes (i 10000)
>>   (parse-time-string "Fri, 13 Feb 2015 14:40:02 +0000")))
>>
>> run faster in a newly started Emacs than in one that has been running
>> for a long time?
>
> Hi Lars,
>
> It becomes slower and slower:


[...]

> after 1 day uptime:
> (3.744592118 19 1.5007945239999572)
> (3.741772863 19 1.5062292100001287)
> (3.744434861 19 1.4990475370001377)
>
> after 2 days uptime:
> (5.104874753 18 1.5796559729999444)
> (5.244741606 20 1.7344523149997713)
> (5.166454389 19 1.6512688520001575)
>
> after 3 days uptime:
> (7.111809223 17 1.6411146469995401)
> (7.200519214 17 1.6629621439999482)
> (7.086889831 18 1.7155860500001836)

Cool!  Then at least we've found the culprit.  :-)

Now we just have to find out why.  Does anybody have any idea?  Could
somebody else also try running the benchmark form up there in a newly
started Emacs and one that's been running for a while to see if they can
reproduce this bug?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no