Adrian Hunter [off-list ref] writes:

On 10/09/21 7:29 pm, Liang, Kan wrote:

quoted

On 9/10/2021 12:04 PM, Peter Zijlstra wrote:

quoted

On Tue, Sep 07, 2021 at 01:45:22PM -0400, Liang, Kan wrote:

quoted

On 9/7/2021 12:39 PM, Adrian Hunter wrote:

quoted

quoted

@@ -4494,8 +4500,16 @@ static int intel_pmu_check_period(struct perf_event *event, u64 value)

       return intel_pmu_has_bts_period(event, value) ? -EINVAL : 0;
   }
+static void intel_aux_output_init(void)
+{
+    /* Refer also intel_pmu_aux_output_match() */
+    if (x86_pmu.intel_cap.pebs_output_pt_available)
+        x86_pmu.assign = intel_pmu_assign_event;
+}

For a hybrid machine, x86_pmu.intel_cap.pebs_output_pt_available is always
cleared. We probably need the PMU specific
pmu->intel_cap.pebs_output_pt_available here.

quoted

+
   static int intel_pmu_aux_output_match(struct perf_event *event)
   {
+    /* intel_pmu_assign_event() is needed, refer intel_aux_output_init() */
       if (!x86_pmu.intel_cap.pebs_output_pt_available)
           return 0;

For a hybrid machine, this always return 0. I think we need to fix it first?

AFAICT the patch is correct for !hybrid, and the hybrid PT muck can then
also fix this up, right?

Yes, for !hybrid, the patch is good.

Since PEBS via PT is temporarily disabled for hybrid for now, the patch set should not bring any issues with hybrid either.
The hybrid PT can be fixed separately.

I don't have much time to look at the hybrid case right now.

Would it be OK to go ahead with these patches?

I'll deal with the PEBS-via-PT on hybrid. As it stands right now, this
patchset is good.

Regards,
--
Alex