On 05/07/2014 09:53 AM, Sasha Levin wrote: > 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.
Aha! > Anything else that might be helpful? No, not too surprising given the info that cpu hotplug was being stressed at the same time. blk-mq doesn't quiesce when this happens, so it's very unlikely that there are races between updating the cpu masks and flushing out the previously queued work. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
