Postfix kqueue(2) support broken

Matthew Dillon dillon at
Wed Sep 16 18:10:38 PDT 2009

:At some time during last months (I can't give exact dates, sry) something 
:broke postfix using kqueue(2) (it's default for DragonFly). I've used 
:postfix for ages on my machines, now it starts up, is able to receive 
:even some mails at best, but stops responding then. I'm able to telnet to 
:the port 25, but postfix doesn't respond.
:$ ps axl | grep master
:    0 27129     1   0 152   0  4908 1756 kqread ILs   ?? 
:0:00.01 /usr/pkg/libexec/postfix/master
:At all kqueue(2) seems to be extremely fragile in DragonFly. There are 
:many packages using it probably just via autodetecting it, but there is 
:packages known to be broken in DragonFly for ages while built with 
:kqueue(2) support. Sysutils/dbus is certainly most notable such one - 
:kqueue(2) support works on every BSD except DragonFly.
:Hasso Tepper

    Hasso, could you generate a kernel panic and kernel core on
    your machine while postfix is stuck in this state?  And upload
    it to leaf?

    I have an idea what might be wrong but I need a kernel core (and
    the related kernel binary of course) to track it down and verify
    the issue.  The thing is the race that I see is really tiny and
    shouldn't regularly effect something like postfix, so I'm not
    sure if I'm looking at the same problem that you are reporting.

					Matthew Dillon 
					<dillon at>

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