lzo2 shows insane speed gap

Kris Kennaway kris at FreeBSD.org
Sun Jan 4 21:25:34 UTC 2009


Christian Weisgerber wrote:
> Bruce Cran <bruce at cran.org.uk> wrote:
> 
>> I'm running 8.0-CURRENT amd64 here on a Turion64 X2 machine. Without
>> malloc debugging (malloc.conf -> aj) 'make test' takes 25s; after
>> removing malloc.conf thus turning on debugging, it takes over 10
>> minutes.
> 
> Wow!  That.  Is.  It.
> 
> Toggling malloc debugging option J makes the "slow" machines "fast"
> and vice versa.
> 
>>> Athlon 64 X2 5200+ 2.6 GHz,      FreeBSD 8.0-CURRENT amd64   ~60 min
> 
> 19 seconds.
> 
> I guess that falls under the "obvious" configuration differences
> to check, but since it usually doesn't cause a significant slowdown
> I completely forgot about it.  Embarrassing.
> 
> But still.  Two orders of magnitude?  That is a pathological case.
> 

Probably it means that lzo2 is doing pathological numbers of mallocs.

Kris


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