X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=examples%2Fvm_power_manager%2Foob_monitor_x86.c;h=a5b1c168c3c86cefa05253ef886881e00edbfc24;hb=4ad736ce03d22e917f7de16fd4ba24d9b49edce9;hp=ebd96b205f0250b799d26943fe9fc769a36f4233;hpb=7e7b7a1f427013374f38e1b101969a1dbce5c9c1;p=dpdk.git

diff --git a/examples/vm_power_manager/oob_monitor_x86.c b/examples/vm_power_manager/oob_monitor_x86.c
index ebd96b205f..a5b1c168c3 100644
--- a/examples/vm_power_manager/oob_monitor_x86.c
+++ b/examples/vm_power_manager/oob_monitor_x86.c
@@ -39,6 +39,7 @@ apply_policy(int core)
 	int64_t hits_diff, miss_diff;
 	float ratio;
 	int ret;
+	int freq_window_idx, up_count = 0, i;
 
 	g_active = 0;
 	ci = get_core_info();
@@ -95,16 +96,43 @@ apply_policy(int core)
 	g_branch_misses = miss_diff;
 
 	if (hits_diff < (INTERVAL*100)) {
-		/* Likely no workload running on this core. Skip. */
-		return -1.0;
+		/* Likely no workload running on this core. */
+		ratio = 0.0;
+	} else {
+		ratio = (float)miss_diff * (float)100 / (float)hits_diff;
 	}
 
-	ratio = (float)miss_diff * (float)100 / (float)hits_diff;
-
-	if (ratio < ci->branch_ratio_threshold)
-		power_manager_scale_core_min(core);
+	/*
+	 * Store the last few directions that the ratio indicates
+	 * we should take. If there's on 'up', then we scale up
+	 * quickly. If all indicate 'down', only then do we scale
+	 * down. Each core_details struct has it's own array.
+	 */
+	freq_window_idx = ci->cd[core].freq_window_idx;
+	if (ratio > ci->cd[core].branch_ratio_threshold)
+		ci->cd[core].freq_directions[freq_window_idx] = 1;
 	else
-		power_manager_scale_core_max(core);
+		ci->cd[core].freq_directions[freq_window_idx] = 0;
+
+	freq_window_idx++;
+	freq_window_idx = freq_window_idx & (FREQ_WINDOW_SIZE-1);
+	ci->cd[core].freq_window_idx = freq_window_idx;
+
+	up_count = 0;
+	for (i = 0; i < FREQ_WINDOW_SIZE; i++)
+		up_count +=  ci->cd[core].freq_directions[i];
+
+	if (up_count == 0) {
+		if (ci->cd[core].freq_state != FREQ_MIN) {
+			power_manager_scale_core_min(core);
+			ci->cd[core].freq_state = FREQ_MIN;
+		}
+	} else {
+		if (ci->cd[core].freq_state != FREQ_MAX) {
+			power_manager_scale_core_max(core);
+			ci->cd[core].freq_state = FREQ_MAX;
+		}
+	}
 
 	g_active = 1;
 	return ratio;