Got this in dmesg after a day's uptime. Not sure what triggered it. SMP kernel running atop a intel Mac Mini. BUG: warning at kernel/cpu.c:56/unlock_cpu_hotplug() (Not tainted) [<c04051db>] dump_trace+0x69/0x1af [<c0405339>] show_trace_log_lvl+0x18/0x2c [<c04058ed>] show_trace+0xf/0x11 [<c04059ea>] dump_stack+0x15/0x17 [<c043c25c>] unlock_cpu_hotplug+0x46/0x6f [<df3972a7>] do_dbs_timer+0x127/0x16b [cpufreq_ondemand] [<c0433c18>] run_workqueue+0x83/0xc5 [<c0434508>] worker_thread+0xd9/0x10d [<c04369db>] kthread+0xc0/0xed [<c0404dab>] kernel_thread_helper+0x7/0x10 DWARF2 unwinder stuck at kernel_thread_helper+0x7/0x10 Leftover inexact backtrace: =======================
Using latest Fedora 6 kernel. $ uname -a Linux paragw 2.6.18-1.2868.fc6 #1 SMP Fri Dec 15 17:32:54 EST 2006 i686 i686 i386 GNU/Linux
http://bugzilla.kernel.org/show_bug.cgi?id=7442 looks similar.
Does not seem to happen with vanilla 2.6.20-rc2 on the same machine. (I assume that WARN_ON will always warn irrespective of any config changes - my kernel config from 2.6.20-rc2 is different from the default Fedora kernel where this error occurs.)
*** This bug has been marked as a duplicate of 214332 ***