On Thu, Jan 6, 2022 at 5:23 PM Borislav Petkov bp@alien8.de wrote:
On Thu, Jan 06, 2022 at 05:12:51PM +0100, Rafael J. Wysocki wrote:
And why can't it be a real use case?
You mean there's someone out there running SMP=n kernels on current hardware which has CPPC too? Yeah, right.
The honest answer is that we don't know.
Moreover, AFAICS the requisite #ifdeffery is there already and the problem is that the init_freq_invariance_cppc() defined in smpboot.c is not exported to modules and the CPPC code is modular in this build.
Yah, I saw that. And that's why I'm saying CPPC should depend on SMP - because it needs that functionality which is defined there.
In fact, the CPPC code itself doesn't need that functionality.
The init_freq_invariance_cppc() call is in there, because amd_set_max_freq_ratio() depends on CPPC and it is pointless to run it when CPPC is not supported, not the other way around.
But if you really wanna support SMP=n, I don't care that much to debate this more - I just think it is silly.
Well, I just don't want to stop supporting SMP=n just because we can't possibly get our build dependencies right.