- Update to 3.3-rc2.

[linux-flexiantxendom0-3.2.10.git] / drivers / cpufreq / cpufreq_ondemand.c

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index c3e0652..6081d57 100644 (file)
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -37,6 +37,7 @@
 #define MICRO_FREQUENCY_MIN_SAMPLE_RATE                (10000)
 #define MIN_FREQUENCY_UP_THRESHOLD             (11)
 #define MAX_FREQUENCY_UP_THRESHOLD             (100)
+#define MAX_DEFAULT_SAMPLING_RATE              (300 * 1000U)
 
 /*
  * The polling frequency of this governor depends on the capability of
@@ -676,6 +677,29 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
                        dbs_tuners_ins.sampling_rate =
                                max(min_sampling_rate,
                                    latency * LATENCY_MULTIPLIER);
+                       /*
+                        * Cut def_sampling rate to 300ms if it was above,
+                        * still consider to not set it above latency
+                        * transition * 100
+                        */
+                       if (dbs_tuners_ins.sampling_rate > MAX_DEFAULT_SAMPLING_RATE) {
+                               dbs_tuners_ins.sampling_rate =
+                                       max(min_sampling_rate, MAX_DEFAULT_SAMPLING_RATE);
+                               printk(KERN_INFO "CPUFREQ: ondemand sampling "
+                                      "rate set to %d ms\n",
+                                      dbs_tuners_ins.sampling_rate / 1000);
+                       }
+                       /*
+                        * Be conservative in respect to performance.
+                        * If an application calculates using two threads
+                        * depending on each other, they will be run on several
+                        * CPU cores resulting on 50% load on both.
+                        * SLED might still want to prefer 80% up_threshold
+                        * by default, but we cannot differ that here.
+                        */
+                       if (num_online_cpus() > 1)
+                               dbs_tuners_ins.up_threshold =
+                                       DEF_FREQUENCY_UP_THRESHOLD / 2;
                        dbs_tuners_ins.io_is_busy = should_io_be_busy();
                }
                mutex_unlock(&dbs_mutex);