Red Hat Bugzilla – Bug 452986
Only one logical CPU seen on beta Tylersburg-EP systems
Last modified: 2008-07-08 09:46:09 EDT
+++ This bug was initially created as a clone of Bug #452912 +++
Description of problem:
When booting either the bare metal or Xen 2.6.18-92.1.6 kernel, only one CPU is
seen on the new beta Tylersburg-EP systems. There should be 16 CPUs with HT
enabled as they're dual quad-core boxes.
Version-Release number of selected component (if applicable):
Kernel and Kernel-xen 2.6.18-92.1.6
Steps to Reproduce:
1. Install RHEL5.2
2. Boot system
3. Only CPU0 can be seen.
4. Update to latest kernels
5. Still only one CPU seen.
1 logical CPU
16 logical CPUs
The system showed 1 logical CPU with the GA 5.2 xen kernel as well. I looked
through the BIOS, but couldn't see any setting that would account for the single
-- Additional comment from email@example.com on 2008-06-25 16:50 EST --
Turbo mode and HT BIOS settings don't seem to affect this. I tried turning them
off but still only 1 CPU is seen.
There are interesting dmesg entries including a soft lockup, and MCE error and
the phrase "weird, boot CPU (#0) not listed by the BIOS". Will the MCE bank
error be addressed by "Bugzilla Bug 446673: FEAT: RHEL 5.3 extend MCE banks
support for Dunnington, Nehalem, and beyond"? I'm attaching dmesg and a
sosreport, but here's the relevant excerpt from dmesg that I'm talking about.
CPU: L1 I cache: 32K, L1 D cache: 32K
CPU: L2 cache: 256K
CPU: L3 cache: 8192K
using mwait in idle threads.
CPU: Physical Processor ID: 0
CPU: Processor Core ID: 0
MCE: warning: using only 9 banks
CPU0: Thermal monitoring enabled (TM1)
SMP alternatives: switching to UP code
Freeing SMP alternatives: 32k freed
weird, boot CPU (#0) not listed by the BIOS.
SMP motherboard not detected.
Using local APIC timer interrupts.
Detected 8.333 MHz APIC timer.
testing NMI watchdog ... OK.
Brought up 1 CPUs
testing NMI watchdog ... <3>BUG: soft lockup - CPU#0 stuck for 10s! [swapper:1]
Modules linked in:
Pid: 1, comm: swapper Not tainted 2.6.18-92.1.6.el5 #1
RIP: 0010:[<ffffffff8000c680>] [<ffffffff8000c680>] __delay+0x6/0x10
RSP: 0000:ffff810110ad9e98 EFLAGS: 00000283
RAX: 000000000008d14c RBX: 0000000000002710 RCX: 00000000236ddd4e
RDX: 0000000000000030 RSI: ffff810110a562c0 RDI: 0000000000252b88
RBP: ffffffff803e5c5c R08: 0000000000000006 R09: ffff8100010203d4
R10: 0000000000000097 R11: ffffffff8015c24b R12: ffffffff803e5c5c
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffffffff8039f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000000000000000 CR3: 0000000000201000 CR4: 00000000000006e0
time.c: Using 1.193182 MHz WALL PIT GTOD PIT/TSC timer.
time.c: Detected 2400.178 MHz processor.
-- Additional comment from firstname.lastname@example.org on 2008-06-25 16:52 EST --
Created an attachment (id=310295)
5.2 non-xen dmesg
This is the entire dmesg output from 2.6.18-92.1.6 non-xen
-- Additional comment from email@example.com on 2008-06-25 16:54 EST --
Created an attachment (id=310296)
sosreport from affected machine
SOSreport from the Tylersburg-EP beta system
-- Additional comment from firstname.lastname@example.org on 2008-06-25 17:11 EST --
Toggling the "Limit CPUID Maximum" setting in BIOS also appears to have no
effect on this issue.
-- Additional comment from email@example.com on 2008-06-25 17:27 EST --
This is a known issue with the current SuperMicro BIOS ACPI Tables. I have read
that SuperMicro is currently working on this issue.
Recommend filing an issue with Intel Premier support so that you will be
notified as soon as a new BIOS is available.
We have received a BIOS update, testing on one Intel SDV system w/ the
supermicro BIOS showed all 16 CPUS. Will be upgrading the remaining SDVs and
racking them for testing.
Remaining systems have been upgraded. Closing out the request as current
release as the BIOS update is available from Intel.