On Thu, May 08, 2014 at 09:27:42PM -0600, Jens Axboe wrote: > On 2014-05-08 21:22, Sasha Levin wrote: > >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? > > Let me put it this way - I'm not surprised that it triggered, but it > will of course be fixed up.
Does reverting 1eaade629f5c47 change anything? The ctx->online isn't changed immediately when cpu is offline, likely there are something wrong. I'm wondering why we need that patch? Thanks, Shaohua -- 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/
