Front page | perl.perl5.porters |
Postings from January 2001
Nick Ing-Simmons wrote:
> How do I get a measure of what sigsetjmp() is costing.
> A very simplistic test gave
>
> With sigsetjmp():
> All tests successful.
> u=0.9 s=0.85 cu=72.37 cs=34.45 scripts=275 tests=21137
>
> With setjmp():
> All tests successful.
> u=1 s=0.75 cu=74.35 cs=35.23 scripts=275 tests=21137
Anything that causes JMPENV_PUSH to be called, eg eval. Ilya did some
work on this the back end of last year, and his tests indicated a
significant speedup in object creation by switching from sigsetjmp to
setjmp - see
http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2000-12/msg00798.html,
there is some test code in there.
Here is another noddy test:
$ time /perl -e 'for ($i=100000;$i;$i--) { eval "die" }'
With sigsetjmp
real 0m28.70s
user 0m25.81s
sys 0m2.76s
With setjmp
real 0m24.20s
user 0m23.93s
sys 0m0.02s
A 15% difference. With XS code you can push a bit harder, so the
difference is more marked. My app does lots and lots of XS-based object
creation/destruction, so I see about 18%.
Alan Burlison
Thread Previous
|
Thread Next