[Python-Dev] GIL behaviour under Windows

[Sturla Molden]

Sturla Molden skrev:
> does not crash the interpreter, but it seems it can deadlock.
>
> Here is what I get con a quadcore (Vista, Python 2.6.3).
>

This what I get with affinity set to CPU  3.

There are deadlocks happening at random locations in ccbench.py. It gets 
worse with affinity set to one processor.

Sturla






D:\>start /AFFINITY 3 /B ccbench.py

D:\>--- Throughput ---

Pi calculation (Python)

threads=1: 554 iterations/s.
threads=2: 257 ( 46 %)
threads=3: 272 ( 49 %)
threads=4: 280 ( 50 %)

regular expression (C)

threads=1: 501 iterations/s.
threads=2: 505 ( 100 %)
threads=3: 493 ( 98 %)
threads=4: 507 ( 101 %)

bz2 compression (C)

threads=1: 455 iterations/s.
threads=2: 889 ( 195 %)
threads=3: 1309 ( 287 %)
threads=4: 1710 ( 375 %)

--- Latency ---

Background CPU task: Pi calculation (Python)

CPU threads=0: 0 ms. (std dev: 0 ms.)
CPU threads=1: 0 ms. (std dev: 0 ms.)
CPU threads=2: 0 ms. (std dev: 0 ms.)
CPU threads=3: 0 ms. (std dev: 0 ms.)
CPU threads=4: 0 ms. (std dev: 0 ms.)

Background CPU task: regular expression (C)

CPU threads=0: 0 ms. (std dev: 0 ms.)
CPU threads=1: 40 ms. (std dev: 22 ms.)
CPU threads=2: 384 ms. (std dev: 179 ms.)
CPU threads=3: 618 ms. (std dev: 314 ms.)
CPU threads=4: 713 ms. (std dev: 379 ms.)

Background CPU task: bz2 compression (C)

CPU threads=0: 0 ms. (std dev: 0 ms.)
CPU threads=1: 0 ms. (std dev: 0 ms.)
CPU threads=2: 0 ms. (std dev: 0 ms.)
CPU threads=3: 0 ms. (std dev: 3 ms.)
CPU threads=4: 0 ms. (std dev: 1 ms.)