Hi Joonwoo,

Recently, I backport EAS1.3 related patches (the latest commit is ec888d46d8993b2bf205ed375e538a3819c23659) on google android-4.4 branch to SPREADTRUM platform(kernel3.18, 4 A53 LITTLE + 4A53 big), and enabled WALT signal, tracing util_avg_pelt(avg.util_avg), util_avg_walt(cumulative_runnable_avg), util_avg_freq(prev_runnable_sum) at the same time. The event ftrace (a game scenario: Subway Surf) is as below:

<idle>-0 [002] dn.3 53.899765: sched_load_avg_cpu: cpu=2 load_avg=306 util_avg=27 util_avg_pelt=57 util_avg_walt=27 util_avg_freq=69 <idle>-0 [000] d.s5 53.899766: sched_load_avg_cpu: cpu=0 load_avg=385 util_avg=0 util_avg_pelt=115 util_avg_walt=0 util_avg_freq=121 UnityMain-4608 [006] d..3 53.899773: sched_load_avg_cpu: cpu=6 load_avg=964 util_avg=0 util_avg_pelt=923 util_avg_walt=0 util_avg_freq=678 UnityMain-4608 [006] d..3 53.899774: sched_load_avg_cpu: cpu=6 load_avg=964 util_avg=0 util_avg_pelt=923 util_avg_walt=0 util_avg_freq=678 <idle>-0 [000] dn.3 53.899813: sched_load_avg_cpu: cpu=0 load_avg=385 util_avg=9 util_avg_pelt=115 util_avg_walt=9 util_avg_freq=121 kworker/u17:2-4204 [001] d..3 53.899830: sched_load_avg_cpu: cpu=1 load_avg=5445 util_avg=223 util_avg_pelt=139 util_avg_walt=223 util_avg_freq=175 kworker/u17:2-4204 [001] d..3 53.899836: sched_load_avg_cpu: cpu=1 load_avg=5445 util_avg=144 util_avg_pelt=139 util_avg_walt=144 util_avg_freq=175 kworker/u17:1-2763 [001] d..3 53.899853: sched_load_avg_cpu: cpu=1 load_avg=5445 util_avg=144 util_avg_pelt=139 util_avg_walt=144 util_avg_freq=175 kworker/u17:1-2763 [001] d..3 53.899858: sched_load_avg_cpu: cpu=1 load_avg=5445 util_avg=100 util_avg_pelt=139 util_avg_walt=100 util_avg_freq=175 adbd-2915 [000] d..3 53.899900: sched_load_avg_cpu: cpu=0 load_avg=385 util_avg=9 util_avg_pelt=115 util_avg_walt=9 util_avg_freq=121 adbd-2915 [000] d..3 53.899907: sched_load_avg_cpu: cpu=0 load_avg=385 util_avg=0 util_avg_pelt=115 util_avg_walt=0 util_avg_freq=121 adbd-2915 [000] d..3 53.899909: sched_load_avg_cpu: cpu=0 load_avg=385 util_avg=0 util_avg_pelt=115 util_avg_walt=0 util_avg_freq=121 mali-event-hnd-2919 [001] d..4 53.899910: sched_load_avg_cpu: cpu=3 load_avg=934 util_avg=0 util_avg_pelt=190 util_avg_walt=0 util_avg_freq=155

From the ftrace, we found that util_avg_walt always hit 0 while

util_pelt&util_avg_freq stay on a relative big value.

Could you give some suggestion for this? Thanks in advance.