fbsd 5.4 python sigprocmask() issue

[Ewan Todd]

Hi,

I ran a python diagnostic on my new 5.3 install this morning comparing
it to a 4.10 install.  Basically, the program was taking 130 seconds
to perform a task that should have taken 70 seconds.  The extra time
is being consumed in system overheads.  A whole bunch of folks
confirmed the problem on a variety of machines with several kernels.
Ultimately, after eliminating processor problems, systemwide kernel
problems etc., python was found to be the culprit.  The discussion
starts at

  http://lists.freebsd.org/pipermail/freebsd-stable/2005-May/014575.html

Suleiman Souhlal ran ktrace(1) on it and discovered that python was
continually calling sigprocmask().

  http://lists.freebsd.org/pipermail/freebsd-stable/2005-May/014591.html

I then ran the same diagnostic in PERL, ruby, and C, and confirmed
that it was a python problem.

  http://lists.freebsd.org/pipermail/freebsd-stable/2005-May/014596.html

There were also a few attempts to speculate what the causes might be,
and suggestions for workarounds.  

I haven't yet had the chance to investigate it further, but I did
say that I would get word to the python porters, so that's what this
message is about.

-e