--- kern_cpu.c.orig 2008-11-08 13:12:24.000000000 -0500
+++ kern_cpu.c 2008-11-08 10:33:18.000000000 -0500
@@ -131,12 +131,16 @@
 DRIVER_MODULE(cpufreq, cpu, cpufreq_driver, cpufreq_dc, 0, 0);
 
 static int cf_lowest_freq;
+static int cf_highest_freq;
 static int cf_verbose;
 TUNABLE_INT("debug.cpufreq.lowest", &cf_lowest_freq);
+TUNABLE_INT("debug.cpufreq.highest", &cf_highest_freq);
 TUNABLE_INT("debug.cpufreq.verbose", &cf_verbose);
 sysctl_NODE(_debug, OID_AUTO, cpufreq, CTLFLAG_RD, NULL, "cpufreq 
debugging");
 sysctl_INT(_debug_cpufreq, OID_AUTO, lowest, CTLFLAG_RW, &cf_lowest_freq, 
1,
 "Don't provide levels below this frequency.");
+sysctl_INT(_debug_cpufreq, OID_AUTO, highest, CTLFLAG_RW, &cf_highest_
freq, 1,
+ "Don't provide levels above this frequency.");
 sysctl_INT(_debug_cpufreq, OID_AUTO, verbose, CTLFLAG_RW, &cf_verbose, 1,
 "Print verbose debugging messages");
 
@@ -295,6 +299,14 @@
 goto out;
 }
 
+ /* Reject levels that are above our specifed threshold. */
+ if (cf_highest_freq > 0 && level->total_set.freq > cf_highest_freq) 
{
+ CF_DEBUG("rejecting freq %d, greater than %d limit\n",
+ level->total_set.freq, cf_highest_freq);
+ error = EINVAL;
+ goto out;
+ }
+
 /* If already at this level, just return. */
 if (cpufreq_CMP(sc->curr_level.total_set.freq, level->total_set.freq)) {
 CF_DEBUG("skipping freq %d, same as current level %d\n",
@@ -617,8 +629,13 @@
 continue;
 }
 
- /* Skip levels that have a frequency that is too low. */
- if (lev->total_set.freq < cf_lowest_freq) {
+ /*
+ * Skip levels that have a frequency that is too low or too
+ * high.
+ */
+ if (lev->total_set.freq < cf_lowest_freq ||
+ (cf_highest_freq > 0 &&
+ lev->total_set.freq > cf_highest_freq)) {
 sc->all_count—;
 continue;
 }