What are all these "Bug: soft lockup" messages about?
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SUSE Linux Enterprise Server 12
May 25 07:23:59 XXXXXXX kernel: [13445315.881356] BUG: soft lockup - CPU#16 stuck for 23s! [yyyyyyy:81602]
followed by various stack traces. This document tries to explain what the soft lockup messages mean.
This 'soft lockup' can happen if the kernel is busy, working on a huge amount of objects which need to be scanned, freed or allocated respectively.
The stack traces of those tasks can give a first idea what the tasks were doing. However, to be able to examine the cause behind the messages, a kernel dump would be needed.
You cannot disable those messages, however in some situations increasing the time when those
soft lockups will be fired can relax the situation.
Do do so just increase the following sysctl parameter: kernel.watchdog_thresh
Default value for this parameter is 10 and to double the value might be a good start.
A TID which explains how to configure and capture kernel dump can be found on the SUSE Support Website.
The watchdog daemon will send an non maskable interrupt (NMI) to all CPUs in the system who in turn print the stack traces of their currently running tasks.
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- Document ID:7017652
- Creation Date:31-MAY-16
- Modified Date:28-AUG-17
- SUSESUSE Linux Enterprise DesktopSUSE Linux Enterprise Server