Subject: Spontaneous reboots
To: None <firstname.lastname@example.org>
From: Brian de Alwis <email@example.com>
Date: 06/26/2003 16:44:04
Forgive this post; I haven't yet subscribed to tech-kern. But I
suspect this is the more appropriate list than current-users.
In spending a tiny bit of time trying to figure out the remrunqueue
panics, noticed that the C version in /sys/kern/kern_synch.c doesn't
actually NULL out the lwp's l_forw pointer.
To check the suspicion that perhaps something was perhaps accidentally
following this pointer, I explicitly NULLed this pointer out too.
--- kern_synch.c 2003/05/20 13:48:08 1.128
+++ kern_synch.c 2003/06/26 23:37:30
@@ -1210,10 +1210,11 @@
prev = l->l_back;
- l->l_back = NULL;
next = l->l_forw;
prev->l_forw = next;
next->l_back = prev;
+ l->l_back = NULL;
+ l->l_forw = NULL;
if (prev == next)
sched_whichqs &= ~(1 << whichq);
This seems to make sense to me, but I've since noticed several
spontaneous reboots, with no messages to /var/log/messages; which
is of little surprise, since remrunqueue is pretty low-level.
Note that I never get dumped to DDB, as I set ddb.onpanic=0 since
I run X normally; but given that previous panics always log something
to /v/l/messages, I don't know if that would have happened either.
I hope this little data point might help.
Brian de Alwis | Graduate student | Software Practices Lab | UBC
"Passivity & cynicism have always come easily to the educated." - Ed Broadbent