On 05/07/2014 11:55 AM, Jens Axboe wrote: > 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.
So this warning is something you'd expect when CPUs go up/down? Thanks, Sasha -- 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/
