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

Christian Tismer tismer at stackless.com
Tue Mar 2 21:22:51 EST 2004

Neal Norwitz wrote:

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, btype and blevel 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 COMAXBLOCKS. I was able to drop the size to under 256 bytes. But perf was still a bit off.

I think instead of or in addition to folding block items, the maximum size of the blockstack could be computed at compile time, instead of a fixed 20 level deep structure. It would complicate things a little more, again, but memory savings would be great.

ciao - chris

p.s.: For a small but simple saving: f_tstate can be completely dropped. Did it for Stackless, already. Maybe I'll submit a patch. :-)

-- Christian Tismer :^) <mailto:tismer at stackless.com> Mission Impossible 5oftware : Have a break! Take a ride on Python's Johannes-Niemeyer-Weg 9a : Starship http://starship.python.net/ 14109 Berlin : PGP key -> http://wwwkeys.pgp.net/ work +49 30 89 09 53 34 home +49 30 802 86 56 mobile +49 173 24 18 776 PGP 0x57F3BF04 9064 F4E1 D754 C2FF 1619 305B C09C 5A3B 57F3 BF04 whom do you want to sponsor today? http://www.stackless.com/

More information about the Python-Dev mailing list