Performance with python and FreeBSD 7.0 amd64

[Andrew MacIntyre]

Felipe Neuwald wrote:

> We have a few servers running zope + plone. On one server running
> FreeBSD 6.3-STABLE i386, I got no problems, but, with one server
> running FreeBSD 7.0-STABLE amd64, same versions of applications, I got
> some errors, like the following:
> 
> dmesg result:
> pid 74775 (python), uid 1002: exited on signal 11

segmentation violation

{...}
> pid 75949 (python), uid 1002: exited on signal 10

bus error

{...}
> pid 75999 (python), uid 1002: exited on signal 4

illegal instruction

{...}


Hmm... that's an interesting mix of failures.

I have seen bus errors when Python runs out of stack space either in the
main thread or child threads (not an unknown issue with Zope).

gcc 4.x in my limited experience generates sometimes noticeably larger
stack frames than gcc 3.x (which is standard on 6.x), which can provoke
unexpected stack exhaustion.

You don't mention whether you're using a local build or a binary package.
Nor do you mention the point release (python 2.4.5 is the most recent in
the 2.4 series).

The default thread stack size according to my 6.3 box's ports is 1MB for
Python 2.4.4) which should be adequate for most circumstances.

The illegal instruction failure suggests something wrong with your
binaries (including those built for Zope).

The segmentation violations often indicate a problem with reference
counts, frequently attributable to bugs in 3rd party extensions.

You might want to check that all binaries for Python, Zope & Plone (if 
it has any) link against the same libraries.

If you can snaffle cores, you might want to try and extract backtraces
from gdb (debugging symbols would make this more productive...)

-- 
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Andrew I MacIntyre                     "These thoughts are mine alone..."
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