[Python-Dev] Removing the GIL (Me, not you!)

[Justin Tulloss]

On 9/13/07, Adam Olsen <rhamph at gmail.com> wrote:
>
>
> Basically though, atomic incref/decref won't work.  Once you've got
> two threads modifying the same location the costs skyrocket.  Even
> without being properly atomic you'll get the same slowdown on x86
> (who's cache coherency is fairly strict.)




I'm a bit skeptical of the actual costs of atomic incref. For there to be
contention, you would need to have to be modifying the same memory location
at the exact same time. That seems unlikely to ever happen. We can't bank on
it never happening, but an occasionally expensive operation is ok. After
all, it's occasional.

Justin
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