[Python-Dev] GIL behaviour under Windows (original) (raw)

Sturla Molden sturla at molden.no
Wed Oct 21 17:38:13 CEST 2009

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.)

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