One word: profile. Looking at stat counts alone rather than measuring the total time spent in all types of system calls from strace and profiling is not really useful. ;)
Another thing to keep an eye out for within a startup profile: how often does the gc collect? our default gc collection thresholds haven't been tuned in ages afaik [or am i forgetting something] and I know of pathological cases at work where simply doing a gc.disable() before importing a bunch of modules (tons of generated protocol buffer code) and re-enabling it afterwards speeds up this application's startup way more significantly than seems healthy in 2.x... that could be related to the particulars of the protobuf module code though. -gps On Sat, Oct 27, 2012 at 4:00 PM, Antoine Pitrou <solip...@pitrou.net> wrote: > On Sun, 28 Oct 2012 01:39:42 +0300 > Serhiy Storchaka <storch...@gmail.com> wrote: > > > On 28.10.12 01:06, Brett Cannon wrote: > > > I really doubt that as the amount of stat calls is significantly > reduced > > > in Python 3.3 compared to Python 3.2 (startup benchmarks show Python > 3.3 > > > is roughly 1.66x faster than 3.2 thanks to caching filenames in a > > > directory). > > > > $ strace ./python -c '' 2>&1 | grep -c stat > > > > Python 2.7 - 161 stats > > Python 3.2 - 555 stats > > Python 3.3 - 243 stats > > This will probably depend on the length of sys.path: > > $ strace -e stat python2.7 -Sc "" 2>&1 | wc -l > 35 > $ strace -e stat python3.2 -Sc "" 2>&1 | wc -l > 298 > $ strace -e stat python3.3 -Sc "" 2>&1 | wc -l > 106 > > $ strace -e stat python2.7 -c "" 2>&1 | wc -l > 200 > $ strace -e stat python3.2 -c "" 2>&1 | wc -l > 726 > $ strace -e stat python3.3 -c "" 2>&1 | wc -l > 180 > > Regards > > Antoine. > > > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org > http://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: > http://mail.python.org/mailman/options/python-dev/greg%40krypto.org >
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