Re: [PATCH] cpufreq: intel_pstate: Use raw_smp_processor_id() in hwp_get_cpu_scaling()

From: Pawan Gupta
Date: Mon Apr 14 2025 - 12:41:39 EST


On Mon, Apr 14, 2025 at 05:19:04PM +0200, Rafael J. Wysocki wrote:
> On Sunday, April 13, 2025 4:44:56 PM CEST srinivas pandruvada wrote:
> > On Sat, 2025-04-12 at 18:34 +0800, Xi Ruoyao wrote:
> > > Use raw_smp_processor_id() instead of plain smp_processor_id() in
> > > hwp_get_cpu_scaling(), otherwise we get some errors on a Lenovo
> > > Thinkpad
> > > T14P Gen 2:
> > >
> > > BUG: using smp_processor_id() in preemptible [00000000] code:
> > > swapper/0/1
> > > caller is hwp_get_cpu_scaling+0x7f/0xc0
> > >
> > > Fixes: b52aaeeadfac ("cpufreq: intel_pstate: Avoid SMP calls to get
> > > cpu-type")
> > > Signed-off-by: Xi Ruoyao <xry111@xxxxxxxxxxx>
> >
> > Acked-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
>
> It's still broken after this patch though because the function should
> use the cpu_data() of the target CPU and not of the CPU running the code.

Sorry for missing that.

I noticed that find_hybrid_pmu_for_cpu() doesn't take the cpu argument.
Does it suffer from the same problem?

init_hybrid_pmu(int cpu)
{
struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
struct x86_hybrid_pmu *pmu = find_hybrid_pmu_for_cpu();