[LU-3897] Hang up in ldlm_pools_shrink under OOM

• Type: Bug
• Resolution: Not a Bug
• Priority: Major
• Affects Version/s: Lustre 2.1.3
• Severity: 3
• Assignee: Zhenyu Xu
• Reporter: Sebastien Buisson (Inactive)

Description

Hi,

Several Bull customers running lustre 2.1.x had a hang in ldlm_pools_shrink on a lustre client (login node).
The system was hung and a dump was initiated from the the bmc, by sending a NMI.
The dump shows there was no more activity on the system. The 12 CPUs are idle (swapper).
A lot of processes are in page_fault(), blocked in ldlm_pools_shrink().
I have attached the output of the "foreach bt" crash command. Let me know if you need the vmcore file.

Each time, we can see a lot of OOM messages in the syslog of the dump files.

This issue looks like LU-2468.

Thanks,
Sebastien.