Summary: | [dummynet] [panic] seldom dummynet panics | ||
---|---|---|---|
Product: | Base System | Reporter: | Eugene Grosbein <ports> |
Component: | kern | Assignee: | Eugene Grosbein <eugen> |
Status: | Closed DUPLICATE | ||
Severity: | Affects Only Me | CC: | eugen, feld |
Priority: | Normal | ||
Version: | 8.2-STABLE | ||
Hardware: | Any | ||
OS: | Any | ||
See Also: | https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=209466 |
Description
Eugene Grosbein
2011-11-14 10:00:23 UTC
Responsible Changed From-To: freebsd-bugs->freebsd-net Over to maintainer(s). Hi! The source of this problem seems to be famous 'dangling pointer' problem: - mbufs with packets from PPPoE users sometimes stall within dummynet queues, - then user disconnects, its ngX interface get destroyed, - then dummynet attempts to dereference its ifp pointer and panic occurs. There is workaround consisting of several tunnables eliminating races: - net.isr.bindthreads=1 in /boot/loader.conf; - net.isr.direct=1 and net.isr.direct_force=1 in /etc/sysctl.conf (default) Plus, use recent 8.2-STABLE as it contains some netgraph fixes for bugs that lead to panics in 8.2-RELEASE and early 8.2-STABLE versions. With these precautions I run my routers rock stable for months. Eugene Grosbein Hi! The same problem had repeated 20 January with FreeBSD 8.3-STABLE built from late October 2012 sources. This time I've got nice crashdump with backtrace. That's with net.isr.bindthreads=1, net.isr.direct=1 and net.isr.direct_force=1. Full crashinfo, kernel.debug and crashdump are available here: http://www.grosbein.net/freebsd/crash/20130120/core.0.txt http://www.grosbein.net/freebsd/crash/20130120/kernel.debug.xz (8.4M) http://www.grosbein.net/freebsd/crash/20130120/vmcore.0.xz Seems to be duplicate of 220078 (unlocked access to INADDR_TO_IFP in the multicast handling code). *** This bug has been marked as a duplicate of bug 220078 *** |