PM / devfreq: memlat: Don't ignore extremely latency sensitive workloads

The ratio value that's compared against ratio_ceil tunable can be 0 for
workloads that are extremely latency sensitive. So, we can't ignore cores
that have a ratio of 0 (which was done to ignore idle cores). So, stop
ignoring cores with a ratio of 0 and instead check for instruction or
frequency being 0 to identify idle cores.

Change-Id: I8c6c14f374f016e6612c3b834589d065bad8f488
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>

diff --git a/drivers/devfreq/governor_memlat.c b/drivers/devfreq/governor_memlat.c
index a3c826e..6a84489 100644 (file)
--- a/drivers/devfreq/governor_memlat.c
+++ b/drivers/devfreq/governor_memlat.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2016, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2015-2017, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -245,7 +245,11 @@ static int devfreq_memlat_get_freq(struct devfreq *df,
                                        hw->core_stats[i].mem_count,
                                        hw->core_stats[i].freq, ratio);
 
-               if (ratio && ratio <= node->ratio_ceil
+               if (!hw->core_stats[i].inst_count
+                   || !hw->core_stats[i].freq)
+                       continue;
+
+               if (ratio <= node->ratio_ceil
                    && hw->core_stats[i].freq > max_freq) {
                        lat_dev = i;
                        max_freq = hw->core_stats[i].freq;