kern/172166: Deadlock in the networking code, possible due to a bug in the SCHED_ULE

[Eugene Grosbein]

The following reply was made to PR kern/172166; it has been noted by GNATS.

From: Eugene Grosbein <egrosbein at rdtc.ru>
To: Andriy Gapon <avg at freebsd.org>
Cc: bug-followup at freebsd.org, Alexander Motin <mav at freebsd.org>
Subject: Re: kern/172166: Deadlock in the networking code, possible due to
 a bug in the SCHED_ULE
Date: Fri, 05 Oct 2012 15:39:58 +0700

 04.10.2012 17:23, Andriy Gapon ÐÉÛÅÔ:
 
 >> Can I have any advice/workaround/bugfix on how to reconfigure my routers
 >> to prevent them from locking this way?
 > 
 > As I said, the primary problem here is the ipmi thread going insane.
 > You can try to remove ipmi driver, if you can afford that.
 > Or you can try to hack on it, so that
 > (1) it voluntary yields even when it thinks that it always has work to do
 > (2) there is some diagnostic on what keeps it running
 > 
 > You may also try to set the thread's priority to PUSER (using sched_prio), but I
 > am not sure what bad side-effects may happen because of that.
 > 
 > No magic bullet here, sorry.
 
 Thank you. As workaround, I've unloaded ipmi.ko
 and edited my scripts to access IPMI sensors over IP instead of local interface.
 
 Eugene Grosbein