On Thu, 13 Aug 2009, Dimitrios Apostolou wrote:
Profiling after my changes seems that now the major slowdown is
simplePkgList()@rpmsack.py so it's worth concentrating the effort there.
I dug a little deeper on this one and am now certain that most CPU time is
needed inside the dbMatch() iterator. Unfortunately this is as far as I
can go since the whole rpm-python module is implemented in C. Nevertheless
I'm wondering, why does a simple listing of ~2K packages needs about 5
seconds. What format is the rpm database in? Wasn't there a big format
change recently that improved the performance? Isn't "rpm -qa" the same as
iterating over dbMatch() with no parameters? If so why there is so big
difference:
$ time python yum/rpmsack.py >/dev/null
real 0m5.481s
user 0m3.568s
sys 0m1.222s
$ time rpm -qa > /dev/null
real 0m27.155s
user 0m22.924s
sys 0m1.506s
Thanks in advance,
Dimitris
P.S. In my previous email I forgot to mention that the usage of
share_data()@misc.py is a slowdown since it is called many thousands
times. Since it doesn't seem to provide an important memory advantage and
it perplexes the code a lot, I have removed it wherever my patch applies.
Indeed this saves some seconds of CPU time.
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