Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

I had two of my CPUs lock up on one of my servers. From dmesg:

BUG: soft lockup - CPU#1 stuck for 23s! [vmx-vcpu-0:6148]

and later:

BUG: soft lockup - CPU#2 stuck for 23s! [vmx-vcpu-0:6148]

I'm trying to figure out why this would happen; the processor has 4 cores with hyperthreading, so the OS sees it as 8 cores. But my main question is related to this:

When looking at htop post-freeze from SSH, I see that CPUs #2 and #3 (guessing these correspond to #1 and #2 from dmesg) are both stuck at 100% with apparently no processes using them:

htop

None of the processes were using more than 5% CPU. Why would these display 100% utilization? Are they still considered locked by the kernel?

share|improve this question
    
What OS/version/kernel/distribution. Also, is this a virtualized guest? –  ewwhite Mar 14 '13 at 1:25
    
@ewwhite Ubuntu Server 12.04 LTS, linux-image-3.5.0-23-generic, bare metal host for some VMs (in VMware Workstation though, not ESX or anything). So far downgrading to Linux 3.5.0-22 seems to resolve the issue, but I can't reliably reproduce it so can't be sure. –  Tom Marthenal Mar 14 '13 at 1:33

1 Answer 1

up vote 2 down vote accepted

As the message reports, this a bug in kernel-level code.

Those CPUs are stuck in a kernel code (vmx-cpu-0) that is not yield()ing control of the CPU for a long period of time.

As far as what to do - open a ticket with VMware. vmx-cpu-0 looks like their code, but I'm not totally sure.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.