On Thu, Nov 23, 2017 at 07:36:23AM +0800, Fengguang Wu wrote:
>On Tue, Nov 21, 2017 at 04:39:14PM +0200, Andy Shevchenko wrote:
>>On Tue, 2017-11-21 at 21:31 +0800, Fengguang Wu wrote:
>>> On Tue, Nov 21, 2017 at 08:33:57PM +0800, Fengguang Wu wrote:
>>> > Hello,
>>> >
>>> > FYI this happens in mainline kernel 4.14.0-02748-gabc36be.
>>> > It shows up since v4.13 .
>>>
>>> Sorry it actually also shows up in 4.10:
>>
>>This one means that interrupt storm is occurred. Last time I saw that
>>was by the fact of some specific IOAPIC configuration when DMA for UART
>>was enabled.
>>
>>I'm pretty sure that is not the case here. Though, it would be nice to
>>see link to the following files:
>
>It's basically a KVM machine. This is adapted from the reproduce
>script attached in the first email:
>
>kvm=(
>        qemu-system-x86_64
>        -enable-kvm
>        -cpu IvyBridge
>        -kernel $kernel
>        -initrd initrd.img
>        -m 1536
>        -smp 2
>        -device e1000,netdev=net0
>        -netdev user,id=net0,hostfwd=tcp::23406-:22
>        -boot order=nc
>        -no-reboot
>        -watchdog i6300esb
>        -watchdog-action debug
>        -rtc base=localtime
>        -drive file=disk-vm-ivb41-1G-7-0,media=disk,if=virtio
>        -drive file=disk-vm-ivb41-1G-7-1,media=disk,if=virtio
>        -drive file=disk-vm-ivb41-1G-7-2,media=disk,if=virtio
>        -drive file=disk-vm-ivb41-1G-7-3,media=disk,if=virtio
>        -drive file=disk-vm-ivb41-1G-7-4,media=disk,if=virtio
>        -drive file=disk-vm-ivb41-1G-7-5,media=disk,if=virtio

>        -serial stdio

Sorry that has been replaced to stdio for convenience of use.
Since this error is related to serial console, it's good to
use the original options used in testing: 

	-serial file:$dmesg
        -serial file:$kmsg

So wrt. your question in the other email, ttyS1 is for writing
kmsg by this script

https://github.com/intel/lkp-tests/blob/master/monitors/kmsg

Thanks,
Fengguang

>        -display none
>        -monitor null
>)
>
>append=(
>        ip=::::vm-ivb41-1G-7::dhcp
>        root=/dev/ram0
>        user=lkp
>        job=/job-script
>        ARCH=x86_64
>        kconfig=x86_64-allyesdebian
>        branch=linus/master
>        commit=abc36be236358162202e86ad88616ff95a755101
>        BOOT_IMAGE=/pkg/linux/x86_64-allyesdebian/gcc-6/abc36be236358162202e86ad88616ff95a755101/vmlinuz-4.14.0-02748-gabc36be
>        max_uptime=600
>        RESULT_ROOT=/result/boot/1/vm-ivb41-1G/debian-x86_64-2016-08-31.cgz/x86_64-allyesdebian/gcc-6/abc36be236358162202e86ad88616ff95a755101/0
>        result_service=tmpfs
>        debug
>        apic=debug
>        sysrq_always_enabled
>        rcupdate.rcu_cpu_stall_timeout=100
>        net.ifnames=0
>        printk.devkmsg=on
>        panic=-1
>        softlockup_panic=1
>        nmi_watchdog=panic
>        oops=panic
>        load_ramdisk=2
>        prompt_ramdisk=0
>        drbd.minor_count=8
>        systemd.log_level=err
>        ignore_loglevel
>        console=tty0
>        earlyprintk=ttyS0,115200
>        console=ttyS0,115200
>        vga=normal
>        rw
>)
>
>Thanks,
>Fengguang