Bug 214332

Summary: BUG: warning at kernel/cpu.c:56/unlock_cpu_hotplug()
Product: [Fedora] Fedora Reporter: Shantanu Goel <sgoel01>
Component: kernelAssignee: Kernel Maintainer List <kernel-maint>
Status: CLOSED NEXTRELEASE QA Contact: Brian Brock <bbrock>
Severity: medium Docs Contact:
Priority: medium    
Version: 6CC: davide.rossetti, fherrera, mgansser, parag.lkml, pix, seanos, selinux, wtogami
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2006-12-06 16:15:27 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Shantanu Goel 2006-11-07 02:21:22 UTC
Description of problem:
Saw the following backtrace on my Core Duo Mac Mini running
kernel-2.6.18-1.2798.fc6.

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
 [<c043c220>] unlock_cpu_hotplug+0x46/0x6f
 [<df3c62a7>] do_dbs_timer+0x127/0x16b [cpufreq_ondemand]
 [<c0433c30>] run_workqueue+0x83/0xc5
 [<c0434520>] worker_thread+0xd9/0x10d
 [<c04369f3>] kthread+0xc0/0xed
 [<c0404dab>] kernel_thread_helper+0x7/0x10
DWARF2 unwinder stuck at kernel_thread_helper+0x7/0x10
Leftover inexact backtrace:

Comment 1 Doug Chapman 2006-11-27 17:00:38 UTC
FYI, looks like rhts hit this on ia64 as well.  changing from i386 to "all".

details of the panic on olympia1 via rhts:

http://rhts.lab.boston.redhat.com/cgi-bin/rhts/test_log.cgi?id=933285


Comment 2 Linda Wang 2006-12-04 17:12:25 UTC
*** Bug 218178 has been marked as a duplicate of this bug. ***

Comment 4 Davide Rossetti 2006-12-05 14:53:16 UTC
I got a couple of these in a raw in less than 24 hours. I'm rebooting now.

>uname -a
Linux hokusai 2.6.18-1.2849.fc6 #1 SMP Fri Nov 10 12:34:46 EST 2006 x86_64
x86_64 x86_64 GNU/Linux

Intel(R) Pentium(R) D CPU 3.00GHz

BUG: warning at kernel/cpu.c:56/unlock_cpu_hotplug() (Tainted: P     )

Call Trace:
 [<ffffffff802691bd>] show_trace+0x34/0x47
 [<ffffffff802691e2>] dump_stack+0x12/0x17
 [<ffffffff802a04ea>] unlock_cpu_hotplug+0x47/0x74
 [<ffffffff883702aa>] :cpufreq_ondemand:do_dbs_timer+0x11c/0x174
 [<ffffffff8024be61>] run_workqueue+0x9a/0xed
 [<ffffffff80248848>] worker_thread+0xf0/0x122
 [<ffffffff80232872>] kthread+0xf6/0x12a
 [<ffffffff8025cda5>] child_rip+0xa/0x11
DWARF2 unwinder stuck at child_rip+0xa/0x11
Leftover inexact backtrace:
 [<ffffffff8029b9e8>] keventd_create_kthread+0x0/0x66
 [<ffffffff8023277c>] kthread+0x0/0x12a
 [<ffffffff8025cd9b>] child_rip+0x0/0x11

Comment 5 Dan Carpenter 2006-12-05 20:48:03 UTC
This is possibly related to bug 215274

Comment 6 Prarit Bhargava 2006-12-06 15:34:31 UTC
Known issue, sorry for the cut-and-paste:

Posted the following patch to lhcs-devel (cut-and-paste):

--- linux-2.6.18.ia64-orig/kernel/cpu.c.orig	2006-10-31 10:57:37.000000000 -0500
+++ linux-2.6.18.ia64/kernel/cpu.c	2006-10-31 10:57:46.000000000 -0500
@@ -58,8 +58,8 @@ void unlock_cpu_hotplug(void)
 		recursive_depth--;
 		return;
 	}
-	mutex_unlock(&cpu_bitmask_lock);
 	recursive = NULL;
+	mutex_unlock(&cpu_bitmask_lock);
 }
 EXPORT_SYMBOL_GPL(unlock_cpu_hotplug);

---

For some reason this hasn't made it into the kernel.  I'll ping akpm about it.

P.

Comment 7 Prarit Bhargava 2006-12-06 16:15:27 UTC
Fixed in 2.6.19.  Will be in next release.

P.

Comment 8 Jarod Wilson 2007-01-02 21:24:30 UTC
*** Bug 220702 has been marked as a duplicate of this bug. ***

Comment 9 Jarod Wilson 2007-01-02 21:26:51 UTC
*** Bug 207916 has been marked as a duplicate of this bug. ***

Comment 10 Jarod Wilson 2007-01-02 21:26:56 UTC
*** Bug 220830 has been marked as a duplicate of this bug. ***

Comment 11 Need Real Name 2007-01-15 03:13:22 UTC
I can still see this bug with 2.6.18-1.2869.fc6 #1 SMP:
Jan 15 03:34:35 localhost kernel: BUG: warning at
kernel/cpu.c:56/unlock_cpu_hotplug() (Not tainted)
Jan 15 03:34:35 localhost kernel:  [<c04051db>] dump_trace+0x69/0x1af
Jan 15 03:34:35 localhost kernel:  [<c0405339>] show_trace_log_lvl+0x18/0x2c
Jan 15 03:34:35 localhost kernel:  [<c04058ed>] show_trace+0xf/0x11
Jan 15 03:34:35 localhost kernel:  [<c04059ea>] dump_stack+0x15/0x17
Jan 15 03:34:35 localhost kernel:  [<c043c25c>] unlock_cpu_hotplug+0x46/0x6f
Jan 15 03:34:35 localhost kernel:  [<f8a682a7>] do_dbs_timer+0x127/0x16b
[cpufreq_ondemand]
Jan 15 03:34:35 localhost kernel:  [<c0433c18>] run_workqueue+0x83/0xc5
Jan 15 03:34:35 localhost kernel:  [<c0434508>] worker_thread+0xd9/0x10d
Jan 15 03:34:35 localhost kernel:  [<c04369db>] kthread+0xc0/0xed
Jan 15 03:34:35 localhost kernel:  [<c0404dab>] kernel_thread_helper+0x7/0x10
Jan 15 03:34:35 localhost kernel: DWARF2 unwinder stuck at
kernel_thread_helper+0x7/0x10

It happened 8 times, but last one was fatal (lot of hard drive activity,
computer became non-responsive).


Comment 12 Seán O Sullivan 2007-01-17 15:27:30 UTC
Occurred in RHEL 5 beta 2 also.
Linux badger.red-hat.eu 2.6.18-1.2747.el5 #1 SMP Thu Nov 9 18:55:30 EST 2006
i686 athlon i386 GNU/Linux
Dual Opteron 246, 2Ghz