When I was using Instruments to test the Display on my phone, I discovered a long-duration frame. Below that frame, there were some gaps in the vsync queue. As I understand it, vsync signals should appear consistently and steadily. How can this behavior be explained?
My phone is iPhone 15 Plus and iOS 18.
Instruments
RSS for tagInstruments is a performance-analysis and testing tool for iOS, iPadOS, watchOS, tvOS, and macOS apps.
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Recently, we reworked a crucial part of our app and managed to half the amount of CPU cycles our app requires (according to Xcode Instruments).
Nonetheless, when using the Time Profiler component in instruments, it shows that the CPU time spent was either higher or the same (depending on execution).
The main time-consuming factor here: libsystem_pthread.dylib - the amount of CPU time spent by this library has doubled from original implementation to reworked implementation.
Therefore, I'm having a few questions:
How should I interpret this result?
How is this even possible if the CPU clock cycles halved?
What is the better metric here, the CPU cycles or the time profiler?
How can I reduce the impact of that said library? What does that library do and how can I influence its performance?
Thanks in advance.
What exactly is included/calculated in the following metrics within RealityKit Trace - RealityKit Metrics - 3D render attributes:
3D Mesh Triangles
Total Triangles Submitted
3D Mesh Vertices
Total Vertices Submitted
As the second part of the question, what differentiates between:
3D Mesh Triangles vs Total Triangles Submitted
3D Mesh Vertices vs Total Vertices Submitted
Can somebody help me find the official documentation for instruments?
Google brings you to this forum, then the link at the top of this forum for Instruments documentation brings you to the Xcode page, which links to these Apple developer docs, wherein a search returns nothing for "Instruments". Searching these Xcode docs for "Instruments" returns only this specific use case on analyzing HTTP traffic.
Topic:
Developer Tools & Services
SubTopic:
Instruments
Hi there,
In a project that I am working on, whenever I try running instruments for allocations to see the memory allocations that are happening under the hood, I see the statistics, and the traces updating, however the chart never updates.
I have made new projects on the machine, and I have tried different Xcode versions, and they all show the chart just fine. I have tried running the project on other machines with no success. I have double checked the arguments and options on the active schema I am trying to profile with the schema of a new project and they are identical.
Here is a picture of how it looks:
My questions are as follows:
What properties and settings can disable the chart from showing up?
What diagnostic steps recommended that I should take?
I can not share a reproducible as this is the only project I have with this problem and it is not mine, but please tell me if there is anything else I can provide in order to debug this.
All the best
Parsa
Topic:
Developer Tools & Services
SubTopic:
Instruments
Tags:
Xcode
Developer Tools
Instruments
Debugging
I cannot my AirPods 3rd gen to my phone it won’t play videos or music when connected. Screen bugs out some times doesn’t see when I swipe. Too many bugs .
There is a WWDC session about this cool instrument to detect hangs on-device:
https://developer.apple.com/videos/play/wwdc2022/10082/
I very like this tool; it's handy and gives useful stack traces, but the threshold of 250 ms is practically too high to use in a testing environment. It would be better if there was an option like 100 ms or something like that.
I think most of the people can see the scrolling hang with a duration of 100-250 ms, and it would be cool to detect such hangs with this instrument.
Is there a way to set a lower threshold, or can Apple consider adding such a threshold?
Thank you!
Topic:
Developer Tools & Services
SubTopic:
Instruments