svn commit: r357165 - head/sys/x86/cpufreq

[Conrad Meyer]

Author: cem
Date: Mon Jan 27 06:04:32 2020
New Revision: 357165
URL: https://svnweb.freebsd.org/changeset/base/357165

Log:
  hwpstate(4): Log a debug line when throttled
  
  If we're going to throttle user requested P-states, we should at least produce
  a debug log line indicating the surprising behavior.
  
  PR:		inspired by 234733

Modified:
  head/sys/x86/cpufreq/hwpstate_amd.c

Modified: head/sys/x86/cpufreq/hwpstate_amd.c
==============================================================================
--- head/sys/x86/cpufreq/hwpstate_amd.c	Mon Jan 27 06:03:36 2020	(r357164)
+++ head/sys/x86/cpufreq/hwpstate_amd.c	Mon Jan 27 06:04:32 2020	(r357165)
@@ -173,8 +173,12 @@ hwpstate_goto_pstate(device_t dev, int id)
 	/* get the current pstate limit */
 	msr = rdmsr(MSR_AMD_10H_11H_LIMIT);
 	limit = AMD_10H_11H_GET_PSTATE_LIMIT(msr);
-	if (limit > id)
+	if (limit > id) {
+		HWPSTATE_DEBUG(dev,
+		    "Restricting requested P%d to P%d due to HW limit\n", id,
+		    limit);
 		id = limit;
+	}
 
 	cpu = curcpu;
 	HWPSTATE_DEBUG(dev, "setting P%d-state on cpu%d\n", id, cpu);