[Python-Dev] [ python-Patches-876206 ] scary frame speed hacks (original) (raw)

Neal Norwitz neal at metaslash.com
Tue Mar 2 21:15:41 EST 2004

On Wed, Mar 03, 2004 at 03:03:19PM +1300, Greg Ewing wrote:

"Phillip J. Eby" <pje at telecommunity.com>:

> Frames are over three times larger than a function and a code object put > together: Yow! I hadn't realised that. Do frames really need to be that big...?

In Include/frameobject.h, b_type and b_level can be combined to a single 32-bit value, rather than two in PyTryBlock. There is a bit more processing to pull the values apart. IIRC, there was a very small, but measurable performance hit. You can also decrease CO_MAXBLOCKS. I was able to drop the size to under 256 bytes. But perf was still a bit off.

My goal was to drop the frame size small enough for PyMalloc. I don't think I ever tried to change the allocs. But since I never got it faster, I dropped it.

Neal

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