On 08.04.2016 [11:04:47 -0000], Louis Bouchard wrote: > Hello, > > Regarding nr_cpus=1, the equivalent maxcpus=1 is set in the kexec > command (at least on default installs) :
Yep, you're right, sorry! > Maybe disabling SMP alltogether by setting maxcpus=0 could be considered > but that shouldn't change much aside from not reserving any SMP data > structure. To Be Tested. Agreed, shouldn't be necessary for this bug. > Regarding kvm_cma_resv_ratio=0, this will avoid the error message but > it has on bearing on the current situation. It failed to allocated it so > the memory was not in use. Right, for correctness, though. > 256Gb of RAM doesn't mean that 128Mb needs to be increased. Here is the > output of free on a 128Gb system right after a kernel panic : On Power, yes it does. Were you on a Power system for the below? Here are the "official" Ubuntu recommendations (https://wiki.ubuntu.com/ppc64el/Recommendations): crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G- 128G:2048M,128G-:4096M This is based upon actual testing on Power by IBM, iirc. Power's memory consumption pattern is very different than x86. Based upon your meminfo output, you were on x86, which is not relevant to this issue. Note the above is architecture-specific -- is it possible to modify kexec-tools to suppor a per-arch crashkernel= default? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1567539 Title: Failure to dump with trusty+3.16 on ppc64el To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/makedumpfile/+bug/1567539/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
