$ perl5.8.8 ~/trash/test.pl
Benchmark: running set_inherited_class, set_inherited_object for at least 3 CPU seconds...
set_inherited_class:  5 wallclock secs ( 3.14 usr +  0.00 sys =  3.14 CPU) @ 403854.65/s (n=1268356)
set_inherited_object:  4 wallclock secs ( 3.16 usr +  0.01 sys =  3.17 CPU) @ 441967.29/s (n=1401865)


$ /usr/local/src/perl-5.10.0-sysmalloc/perl -I/usr/local/src/perl-5.10.0-sysmalloc/lib ~/trash/test.pl 
Benchmark: running set_inherited_class, set_inherited_object for at least 3 CPU seconds...
set_inherited_class:  4 wallclock secs ( 3.15 usr +  0.01 sys =  3.16 CPU) @ 309119.05/s (n=975657)
set_inherited_object:  5 wallclock secs ( 3.08 usr +  0.00 sys =  3.08 CPU) @ 402004.47/s (n=1237420)

$/usr/local/src/perl-5.10.0-perlmalloc/perl -I/usr/local/src/perl-5.10.0-perlmalloc/lib ~/trash/test.pl 
Benchmark: running set_inherited_class, set_inherited_object for at least 3 CPU seconds...
set_inherited_class:  6 wallclock secs ( 3.12 usr +  0.00 sys =  3.12 CPU) @ 378921.38/s (n=1181169)
set_inherited_object:  6 wallclock secs ( 3.15 usr +  0.00 sys =  3.15 CPU) @ 469993.13/s (n=1479744)