On Thu, 04 Jan 2024 15:04:53 +0100 Diederik de Haas
<didi.debian@cknow.org> wrote:
> On Thursday, 4 January 2024 14:34:10 CET Jy Deng wrote:
> > 3. I find that if CONFIG_CPU_FREQ_GOV_POWERSAVE=m, then though such
> > module cannot be in use after boot at once, but it is possible to
> > manually modprobe them. So it may indicate that to use
> > CONFIG_CPU_FREQ_GOV_POWERSAVE=m with CONFIG_MODULE_COMPRESS_XZ=y is
> > actually possible. The problem we find here may be not so fundamental.
>
> That's actually how it always worked.
> $ cat
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_governors
>
> likely only lists 'performance' and 'schedutil'.
> /lib/modules/$(uname -r)/kernel/drivers/cpufreq/ lists several more
governors
> and when you modprobe them, they get added to
'scaling_available_governors'.
> And also to `cpupower frequency-info` -> 'available cpufreq governors'.
>So if you can verify whether it works with 'modprobe' then this is
not a bug.
The problem is that those modules of governors, when without kernel
module compression, they will be automatically loaded. However, when
module compression like CONFIG_MODULE_COMPRESS_XZ is set as 'y', then
I have to manually load them by 'modprobe'. While it is OK to say this
is not a bug, it is also important to find out what makes such difference.