On 2020-12-18 08:22:29 [-0700], Jens Axboe wrote:

Hi,

quoted

Anyway, could you please throw a .config and the test in my inbox so I
can reproduce it and then I will look at this next year.

Attached. The test is just booting my vm, haven't even started running
anything when it triggers. It also seems to be happening throughout
the vm running, at a pretty low rate though.

I tried those patches on my old -next tree, v5.11-rc1 and today's -next
tree. I booted your config with:
| exec qemu-system-x86_64  \
|         -m 4G \
|         -machine q35,accel=kvm \
|         -cpu host \
|         -smp 8 \
|         -kernel "$KERNEL" \
|         -drive file=Deb_sid_amd64-playground_xfs.img,if=virtio,id=diskroot,media=disk,format=raw,discard=on,snapshot=on \
|         -nographic \
|         -append "earlyprintk=ttyS0,115200 console=ttyS0,115200n8 root=/dev/vda1 sysrq_always_enabled ftrace_dump_on_oops nokaslr ignore_loglevel"
|

on an AMD and Intel (due to only CONFIG_CPU_SUP_INTEL=y). Nothing.
Is there anything special in your commandline / disk-setup? After a
complete disk-upgrade I have almost no block-softirqs:

|~# grep BLOCK /proc/softirqs
|       BLOCK:          0          0          0          0          4          0          8          0

Sebastian