Subject: Threading/DNS issues with 2.1RC3?
To: , <>
From: David H.Gutteridge <>
List: current-users
Date: 09/05/2005 00:41:08
Hi all,

Just wondering if anyone else is testing the 2.1 RCs (I've got RC3 running right
now for i386) and has noticed what appear to be problems with threading and/or
DNS lookups which cause applications to hang (so to speak)?

I'm consistently getting hangs when I try and do anything intensive with multi-
threaded web browsers like Firefox, Epiphany (same thing I guess), and Dillo.
When I try opening multiple sites within or between them, things quickly grind
to a halt, the common denominator being DNS queries which don't return.
When I look at what's going on with netstat -na, I see things like this:

udp        0      0
udp        0      0
udp        0      0

(The foreign address is my local DNS server, and there's nothing wrong with it.
In fact, the UDP packets appear not to be getting to it at all.)  These sockets
remain in this state for the life of whatever app opened them.  If I look at
processes with top, I see the processes in question are typically in the netio

All three of those browsers happen to be multi-threaded (Dillo uses threading for
DNS queries); if I crack open lynx or the command-line ftp client, I have no
trouble resolving the same sites that the "big" three are stuck on, and can
conduct things normally.  I can run the very same applications with the same
usage pattern on another box I have running i386/2.0.2 without incident, and
they're all identical versions from pkgsrc.

I tried ktracing a Firefox session, but couldn't see anything revealing
(but I can't claim expertise in this area, so that doesn't mean anything
necessarily).  I haven't built anything with debugging symbols, but will try
that and see what I can get if this isn't an issue that's already been
identified.  I'd thought I'd found the problem
(see:, but that
doesn't seem to be it.