> I see you're comparing 3.2 and default: could you run the same
> benchmark on default with and without the patch ?

Same results:
-> default branch:
1000 loops, best of 3: 364 usec per loop
-> default branch with patch reverted:
10000 loops, best of 3: 185 usec per loop

(with kernel 2.6.38.8-desktop-8.mga and glibc-2.12.1-11.2.mga1)

And I can reproduce on another machine:

-> default branch:
1000 loops, best of 3: 224 usec per loop
-> default branch with patch reverted:
10000 loops, best of 3: 88 usec per loop

(Debian stable with kernel 2.6.32-5-686 and glibc 2.11.2-10)