Re: 4.14: WARNING: CPU: 4 PID: 2895 at block/blk-mq.c:1144 with virtio-blk (also 4.12 stable)

From: Christian Borntraeger
Date: Wed Nov 29 2017 - 14:36:58 EST



On 11/29/2017 08:18 PM, Christian Borntraeger wrote:
> Works fine under KVM with virtio-blk, but still hangs during boot in an LPAR.
> FWIW, the system not only has scsi disks via fcp but also DASDs as a boot disk.
> Seems that this is the place where the system stops. (see the sysrq-t output
> at the bottom).

FWIW, the failing kernel had CONFIG_NR_CPUS=256 and 32 CPUS (with SMT2) == 64 threads
with CONFIG_NR_CPUS=16 the system booted fine.