[Pan-users] Re: freeze, high CPU getting new headers

[walt]

On Mon, 04 Aug 2008 20:46:00 +0000, Matthijs Benschop wrote:

> Op Mon, 04 Aug 2008 19:40:40 +0000, schreef walt:
>> 
>> Just occurred to me that I don't use any filters, so the 'apply_filter'
>> step in my case would be a null_op.  What about you (and David)?
> 
> No filters enabled here (unless they're configured somewhere I dont
> know)

Hm.  Duncan was right -- I was thinking of scoring so this isn't it.

> Btw, I verified running my same distro but 32bit version (same
> packages), and no problems at all. Maybe 64bit issue..? Triggered by
> something else in the system (because it ran fine until few months back)

Seems to me I've read several times that 64-bit gcc and friends are not
really ready for prime time yet, but that's hearsay, not experience.
Are you running ubuntu also?

> Is the gdb output of any use? I have some more which are a little
> different.

Yes, what you are doing here is taking random samples and looking for
places in the code that appear in every sample.  For example your
backtraces all include calls to MyTree::add_articles. This depends on 
statistics, and you know how *they* behave.  I personally would start
with strace because it will print every system call, not just random
ones.

Have you used strace before?  It's pretty simple to run, not so easy
to interpret the output sometimes.  Example:  use 'top' to find the
process that's using up the cpu, and then start strace like this:
#strace -p pid-of-greedy-process
and be prepared for tons of output to the console (or you can send
it to a file instead with the -o flag).  Because pan is stuck in
a loop somewhere, you should have plenty of data in two seconds or
so, then hit Ctrl-C to stop strace.  Then the trick is to find a
repeating pattern near the end of the strace output where you see
the same system calls over and over again, and that should point
you to what pan is doing with all those cpu cycles.  That's the
theory :o)

>     at ../../pan/data/data.h:442
> #19 0x00000000004efd89 in pan::DataImpl::MyTree::add_articles
> (this=0x292e330, nodes_in=<value optimized out>) at my-tree.cc:534 #20
> 0x00000000004f05a9 in pan::DataImpl::MyTree::apply_filter
> (this=0x292e330, address@hidden) at my-tree.cc:235 #21
> 0x00000000004f0d9a in pan::DataImpl::MyTree::add_articles