Re: Using QEMU to performance test Linux kernel

[Philippe Mathieu-Daudé]

Hi Paul,

On 15/8/24 23:23, Paul Menzel wrote:
> Dear QEMU folks,
>
>
> I would like to boot a Linux kernel image several times, and log the 
> output – case in point [1] it would be booting with `initcall_debug`, 
> and look at how long `acpi_init()` took to execute.
>
> I came up with
>
>      qemu-system-x86_64 -enable-kvm -smp cpus=2 -m 1G -nographic -kernel 
> /boot/vmlinuz-6.11.0-rc3-00007-gd74da846046a -append "initcall_debug 
> console=ttyS0"
>
> but it hangs, as no bootable image is found. There are probably a lot of 
> ways to reboot it (initrd, wrapper script, …). What is the “easiest” way?

Guenter uses QEMU with "-no-reboot -append 'panic=-1 noreboot'"
for the linux-build-test suite:
https://github.com/groeck/linux-build-test

You should see on the console:

  reboot: Restarting system

(we also use it in our functional tests, see
tests/avocado/boot_linux_console.py).

Regards,

Phil.

> [1]: 
> https://lore.kernel.org/linux-acpi/20240808222138.51-1-colin.king@intel.com/