Re: blk-mq: WARN at block/blk-mq.c:585 __blk_mq_run_hw_queue

Sasha Levin
2014-05-07T15:53:18Z

On 05/07/2014 11:45 AM, Jens Axboe wrote:
> On 05/07/2014 09:37 AM, Sasha Levin wrote:
>> Hi all,
>>
>> While fuzzing with trinity inside a KVM tools guest running the latest -next
>> kernel I've stumbled on the following spew:
>>
>> [ 986.962569] WARNING: CPU: 41 PID: 41607 at block/blk-mq.c:585 __blk_mq_run_hw_queue+0x90/0x500()
>
> I'm going to need more info than this. What were you running? How as kvm
> invoked (nr cpus)?

Sure!

It's running in a KVM tools guest (not qemu), with the following options:

'--rng --balloon -m 28000 -c 48 -p "numa=fake=32 init=/virt/init zcache ftrace_dump_on_oops debugpat kvm.mmu_audit=1 slub_debug=FZPU rcutorture.rcutorture_runnable=0 loop.max_loop=64 zram.num_devices=4 rcutorture.nreaders=8 oops=panic nr_hugepages=1000 numa_balancing=enable'.

So basically 48 vcpus (the host has 128 physical ones), and ~28G of RAM.

I've been running trinity as a fuzzer, which doesn't handle logging too well,
so I can't reproduce it's actions easily.

There was an additional stress of hotplugging CPUs and memory during this recent
fuzzing run, so it's fair to suspect that this happened as a result of that.

Anything else that might be helpful?

Thanks,
Sasha