← Back to team overview

kernel-packages team mailing list archive

[Bug 1546159] Re: ISST-LTE: high cpus number need a high crashkernel value in kdump

 

** Package changed: ubuntu => linux (Ubuntu)

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1546159

Title:
  ISST-LTE: high cpus number need a high crashkernel value in kdump

Status in linux package in Ubuntu:
  New

Bug description:
  ---Problem Description---
  The kdump kernel will be booted with "maxcpus=1", so no matter how many cpus this system has, only one cpu will be brought up during kdump I think. But on LPAR thymelp2, if we allocate 40 cpus on it, then kdump works just fine with 512M  as crashkernel value. But if we allocate 200 cpus on it, kdump fails by trggering OOM. It has been proved that in latter situation we need 1.5G RAM reserved for kdump to let it works.
   
  ---Steps to Reproduce---
   1. configure kdump with crashkernel=512M on thymelp2
  2. allcoate 40 cpus on thymelp2 and trigger kdump
  3. allocate 200 cpus on thymelp2 then do kdump again
   
  ---
  Mahesh has posted a patch upstream to provide support for nr_cpus in kdump kernel.
  That should take care of this problem..

  https://lists.ozlabs.org/pipermail/linuxppc-dev/2016-February/138619.html
  ---

  Heads up Canonical: We'll want this patch included as soon
  possible/practical.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1546159/+subscriptions