1. how locate bottlenecks?
The first step, look fps; (1) the average fps; (2) the frame rate consistency, there is no Caton, dropped frames. The average of 42, but will fall in the rendering stage 37. Trace tab, gpu activity, cpu Scheduling is the primary measure.
rendering stage that the implementation of the gpu. There are surface, channel.
gpu activity to see the interaction between the cpu and gpu.
cpu cpu scheduling can see the implementation of each core. To see if there are scheduling problems.
1. see if gpu is the bottleneck. Sign in realtime page, look gpu utilization, if gpu utilization is high; at trace tab, see Surface between spaced, described gpu bottleneck;
Below this gpu utilization 98-100, described gpu bottleneck.
Further, in the trace, gpu Activity co gpu stages below. Referring also, as shown, is not the bottleneck GPU:
And, as shown below, GPU bottleneck:
2. If the gpu is not the bottleneck, then see if cpu is the bottleneck.
Sometimes cpu utilization is very low, but also could be cpu bottleneck. Because the cpu is multi-core. This time to see the cpu scheduling.
cpu6 seems to be a bottleneck.
Then look at the core of what is the bottleneck.
You can see, SatisfyConstraints function is the bottleneck. Modify the function, after multiple threads to get,
cpu no longer the bottleneck.
(3) vertical synchronization Bottleneck
If not gpu, cpu, there may be a vertical sync is limited. That game run to reach that speed the display screen. We can see this:
Frame time is about 16ms (60fps), at the end of the frame, cpu and gpu are waiting surface rendering. That game refresh rate has been run as a screen.
But even if the game had vertical sync is limited, and there is still potential for optimization, in addition to increase the frame rate beyond.
More app problem is that large power consumption. So, still we have to optimize the code, with fewer resources, running at a lower temperature of the machine, do less work to achieve higher frame rates. On the low-end devices, performance is still very good.
参考链接：https://developer.qualcomm.com/software/snapdragon-profiler/app-notes/identify-application-bottlenecks