[Public]
> -----Original Message-----
> From: Jan Beulich <jbeul...@suse.com>
> Sent: Thursday, June 12, 2025 12:10 AM
> To: Penny, Zheng <penny.zh...@amd.com>
> Cc: Huang, Ray <ray.hu...@amd.com>; Andrew Cooper
> <andrew.coop...@citrix.com>; Roger Pau Monné <roger....@citrix.com>;
> Anthony PERARD <anthony.per...@vates.tech>; Orzel, Michal
> <michal.or...@amd.com>; Julien Grall <jul...@xen.org>; Stefano Stabellini
> <sstabell...@kernel.org>; xen-devel@lists.xenproject.org
> Subject: Re: [PATCH v5 04/18] xen/cpufreq: introduce new sub-hypercall to
> propagate CPPC data
>
> On 27.05.2025 10:48, Penny Zheng wrote:
> > @@ -635,6 +641,124 @@ out:
> > return ret;
> > }
> >
> > +static void print_CPPC(const struct xen_processor_cppc *cppc_data) {
> > + printk("\t_CPC: highest_perf=%u, lowest_perf=%u, "
> > + "nominal_perf=%u, lowest_nonlinear_perf=%u, "
> > + "nominal_mhz=%uMHz, lowest_mhz=%uMHz\n",
> > + cppc_data->cpc.highest_perf, cppc_data->cpc.lowest_perf,
> > + cppc_data->cpc.nominal_perf,
> > cppc_data->cpc.lowest_nonlinear_perf,
> > + cppc_data->cpc.nominal_mhz, cppc_data->cpc.lowest_mhz); }
> > +
> > +int set_cppc_pminfo(unsigned int acpi_id,
> > + const struct xen_processor_cppc *cppc_data) {
> > + int ret = 0, cpuid;
> > + struct processor_pminfo *pm_info;
> > +
> > + cpuid = get_cpu_id(acpi_id);
> > + if ( cpuid < 0 || !cppc_data )
>
> The !cppc_data part isn't really needed, is it?
I added it because set_cppc_pminfo() is an external function, and maybe we
shall validate each
input for any external functions? Or maybe not. I'm not sure if it is a MUST?
>
> > + pm_info->init = XEN_CPPC_INIT;
> > + ret = cpufreq_cpu_init(cpuid); #ifndef NDEBUG
> > + if ( ret )
> > + dprintk(XENLOG_WARNING,
> > + "CPU %u failed to be initialized with amd-cppc mode,
> > and users
> could only reboot and re-define cmdline with \"cpufreq=xen\"",
> > + cpuid);
> > +#endif
>
> What use if the #ifdef here? The more that NDEBUG controls behavior of
> ASSERT(), not that of (debug) logging.
>
Understood. Maybe I shall use one-time printk_once()
>
> Jan
