We‘ve just released ARM DS-5 Development Studio v5.22 and we have made Streamline more powerful and user-friendly. In this blog, I will highlight the major changes in the latest version. For a more detailed list of enhancements and fixes, please see the changelog.
Android trace events alongside extensive list of standard system events
Android supports trace events and these events are written to a system trace buffer. We can use Systrace tool, provided by Android, to collect and visualize these events. In DS-5 v5.22 release, we have enhanced Streamline to support Android trace events. We can now see the performance counters and charts like CPU and GPU activity alongside standard Android trace events.
Figure 1 Streamline showing Android trace events
For example, in the above capture, you can inspect the frame by looking at various Android Surfaceflinger events like onDraw and eglSwapBuffers.
Profile Mali-T400 Series GPUs without having kernel source
Streamline requires an agent called gator to be installed and running on the ARM Linux target. Gator can operate in two modes
(a) kernel space gator – using a kernel module called gator.ko.
(b) user space gator – without the kernel module.
As user space gator is restricted to using user space APIs, it does not support all the features that kernel space gator supports. However user space gator is more easy to use as you do not need the target’s Linux kernel source to build the kernel module. Given the ease of use, we are working towards enhancing the features supported by user space gator. With this release, we are happy to announce that user space gator now supports Mali-T400 series of GPUs. Note that you will need a recent version of Mali DDK, which exports system events to the user space. Going forward, you can expect us to add support for more Mali graphics processors.
Automatic fetch of symbol and other information from files on the target
Streamline needs symbol information to co-relate the events captured and the code being run. In the past, we had to manually provide this image information. This can be tricky if image is available only on the target but not on the host. In the v5.22 release, we have introduced automatic image transfer from the target feature to handle this situation.
Figure 2 New textbox to select processes for automatically fetching of image from the target
This is best shown with an example. In my case, I want to run the dhrystone executable on my Nexus 9 and see the function profile. As a first step, I run the program via adb, and start the Streamline session. During the session, I can now see a new box at the bottom, as seen in the above picture. Here, I can type a pattern (“dhr” in my case) to select the list of processes. Streamline will automatically fetch symbol information for these selected processes from the target. In my case, I can see that Streamline shows function profile for dhrystone, as seen in the below picture, without having to provide image manually.
Figure 3 Streamline showing function profile for the dhrystone process
Streamline snippet during the live capture
Streamline snippet is now available during live capture. As you might recall, Streamline snippet is a powerful feature where users can track complex counters, derived from a combination of more basic counters. For example, as seen in the below picture, you can track ClockPerInstruction (CPI) using $ClockCycles and $InstructionExecuted counters.
Figure 4 CPI snippet
DS-5 v5.22 comes with an enhanced Streamline with useful features like support for Android trace events, automatic symbol loading from target, profiling with user-space gator library for Mali-T400 series GPUs amongst others. You can get all these features and more by downloading DS-5 v5.22 from here. Sign up to the DS-5 newsletter and get updates, blogs and tutorials delivered to your inbox.