Instruments

RSS for tag

Instruments is a performance-analysis and testing tool for iOS, iPadOS, watchOS, tvOS, and macOS apps.

Instruments Documentation

Posts under Instruments subtopic

Post

Replies

Boosts

Views

Activity

Touch screen stops working on shutdown screen in single app mode
We have 2 iPhones (16 pro - iOS 18.2, 16 regular - iOS 18.5 ) in single app mode and sometimes we need to shut them down manually. After holding Power and VolumeUp, shutdown screen appears as usual, but the slider isn't responding to touch, as well as the whole screen. After force restart using volume buttons, this issue disappears, but reappears after next phone restart. If we disable single app mode -the issue is gone and touch screen works every time on shutdown screen. Both iPhones share the same behavior. Is there any other way to reliably shut down the iPhone locally without using MDM or a way to fix this issue?
2
0
149
Aug ’25
"Processor Trace cannot profile this process without proper permission"
Hello, I'm no macOS 26.1 I'm running through the example shown in the WWDC video "Optimizing CPU Performance with Instruments." After right-clicking a test, clicking "Profile...", and trying to run a processor trace I get the error in the subject. I have processor trace enabled on the CPU via system settings. I confirmed this by disabling it and re-enabling it and noting the error that appears when this is disabled is different from the one I'm now getting. This did previously work but I haven't tried since macOS 26 is released. Is there something new I need to be doing to my Xcode project settings in order for this to be working?
2
0
169
3w
Accessing Built-In iOS Alarm Sounds When Using AlarmKit
Hi everyone, I’m currently integrating AlarmKit into an app and would like to offer users the same selection of built-in iOS alarm sounds that the native Clock app provides. So far, I haven’t found any API in AlarmKit (or elsewhere in the SDK) that exposes the system’s default alarm tones. Before implementing a custom sound library, I wanted to check: Is there any way to access or present the iOS system alarm sounds when creating alarms with AlarmKit? Or are developers limited to custom audio files that we provide ourselves? If anyone has experience with AlarmKit or knows whether this is technically possible (or explicitly restricted), I’d really appreciate your insights. Thanks!
2
0
191
Dec ’25
Instruments has an error and a typo
* [Error] Failed to stop recording session: Failed stoping ktrace session. (xcode-select version 2409) So why can't it stop the ktrace session? And how long has that typo been around? 😄 (Look, I've kept typos in log messages for years because it differentiated that message from other messages.)
1
0
340
Feb ’25
Memory leak in SwiftUI when pressing keys (detected by instruments)
I've discovered what appears to be a system-level memory leak when pressing any key in Swift UI projects. This issue occurs even in a completely empty SwiftUI project with no custom code or event handlers. When monitoring with Instruments' Leaks tool, I observe multiple memory leaks each time any key is pressed. These leaks consist primarily of: NSExtraData objects (240 bytes each) NSMenuItem objects (112 bytes each) Other AppKit and Foundation objects Has anyone else encountered this issue? How can I fix this behavior? While the leaks are small (about 5-6KB per keypress), they could potentially accumulate in applications where keyboard input is frequent.
1
0
108
Mar ’25
(iOS 26) - PowerProfiler trace file cannot be opened
I kept CoreLocation’s startUpdatingLocation running for a full day and used Performance trace - PowerProfiler to track the power usage during that time. The trace file was successfully generated on the iOS device, and I later transferred it to my MacBook. However, when I tried to open the .atrc file, I received the following warning: The document cannot be imported because of an error: File ‘/Users/jun/Downloads/PowerProfiler_25-06-16_181049_to_25-06-17_091037_001.atrc’ doesn’t contain any events. Why is this happening? Is there a known issue with PowerProfiler in iOS 26, or am I missing something in the tracing setup? Note: The .aar file and the extracted .atrc file are not attached here, as forum uploads do not support these formats.
1
0
183
Jun ’25
Bottleneck analysis is not available in my Instruments
Hello, I wanted to try new Bottleneck analysis mode showcased in recent Apple's video, however when I select CPU Counters template in Instruments, there's no such option - just the same old "sample by Time/Events". I have the latest XCode 16.4 and OS Sonoma 15.5, the system is M4 Max. While Instruments shows version 16.0 in About dialog for some reason (a bug?), it definitely comes from the Xcode 16.4 package and the build id is the same (16F6) as for XCode 16.4. I also checked just in case on another M1 system (all updated as well) and it's all the same. Any clues why Bottleneck analysis is missing? Regards, Maxim
1
0
202
Jul ’25
Question about Metrics Analysis in Xcode 26
Hello, I have recently been using the new Power Profiler tool introduced in Xcode 26 to analyze the power consumption of my app. My app primarily operates in the background. During a profiling session of 5 hours and 30 minutes, I observed that the app was active in the background for 2 hours and 30 minutes, while it remained in a suspended state for the remaining 3 hours. While the Power Profiler allows me to identify spikes in CPU, networking, and other resource usage at specific points, it is difficult to determine whether these values are objectively considered high. For example, in my case, the total QoS Execution Time of CPU Impact recorded during the 5 hours and 30 minutes was 12.18 seconds. I am wondering whether this is considered a good metric. Could you please advise on the following points? 1. Is there a commonly accepted or recommended ratio between app active time and CPU time that developers should aim for? 2. Are there any guidelines or reference materials on how to interpret CPU usage and other resource metrics for apps that primarily run in the background? Any insights or advice would be greatly appreciated. Thank you.
1
0
202
Aug ’25
Complete control flow trace... possible?
Is there an xctrace instrument capable of capturing the complete control flow of a process? So far the best I can find is high-frequency sampling, but what I need is a trace of all machine instructions executed. This is easily done on Linux/Intel using the perf tool, which provides access to Intel's hardware-assisted tracing module (ptrace). According to the arm specification, my mac mini M1 (armv8.4-a) and M4 (armv9.2-a) both have hardware support in the CoreSight ETM (embedded trace macrocell) for full instruction tracing (i.e., no sampling, no gaps, no statistics--capturing the complete execution path). But it's not clear how I can access these features, if they are supported by the macos XNU kernel at all. After hours of searching online, it's nothing but dead ends. Any suggestions for documentation or Xcode tools or open-source tools or built-in macos tools would be much appreciated!
1
0
168
Aug ’25
Instruments Failure in Xcode 16.4
Updated Xcode from 16.2 to 16.4, running Time Profile in Instruments, it launches the trace, but does not install or load on connected device, breaks the functionality. I am unable to debug... ERROR: Connection with the remote side was unexpectedly closed : <dictionary: 0x1f3c8b6d0> { count = 1, transaction: 0, voucher = 0x0, contents = "XPCErrorDescription" => <string: 0x1f3c8b850> { length = 22, contents = "Connection interrupted" } } Domain: IXRemoteErrorDomain Code: 6 User Info: { DVTErrorCreationDateKey = "2025-08-09 00:47:53 +0000"; } -- Connection with the remote side was unexpectedly closed : <dictionary: 0x1f3c8b6d0> { count = 1, transaction: 0, voucher = 0x0, contents = "XPCErrorDescription" => <string: 0x1f3c8b850> { length = 22, contents = "Connection interrupted" } } Domain: IXRemoteErrorDomain Code: 6 IOS 18.5
1
0
260
Aug ’25
Capturing the instruction trace from the ARM ETM
According to the ARM documentation for the CPU models available in Apple Silicon, the CoreSight implementation includes an Embedded Trace Macrocell which can perform a complete "Instruction Trace" (https://developer.arm.com/documentation/102119/0200/What-is-trace-). Although other operating systems such as Linux make this easy, we have not been able to find any tools or even a system-level API for accessing this feature of the ETM. In the "Instruments" window of Xcode 16+, there is a "Processor Trace" instrument, but this performs sampling and is totally unrelated to the Instruction Trace we need for debugging and analysis purposes. Because it produces a complete, contiguous sequence of branch instructions, the Instruction Trace is essential for identifying precise execution behaviors that are otherwise invisible to the developer. On other platforms, an alternative is debugger scripting, but we have found far too many bugs and reliability issues with the macOS implementation of lldb. Any suggestions would be greatly appreciated!
1
0
250
Sep ’25
Crash when trying to use instruments memory debugging
Hello, I am trying to investigate my apps memory usage using the instruments tool. Whenever I attach instruments my app crashes, when I have it connected to xcode as well I can see that the crash occurs in liboainject: ___lldb_unamed_symbol117 with SIGBUS. Here's what the stack looks like. Is this a known issue? Are there any workarounds or things I can do to figure out what is causing the crash?
1
0
111
Nov ’25
How to help Instrument's Swift task task lifetime summary group the same tasks so that the count for tasks is not always 1.
This is a screenshot from the Swift Task track in Xcode. I made these tasks with public actor ResourceManager { func foo() { for observer in observers { Task(name: "ResourceManager notify observers") { await notification(observer) } } } } I am confused why each of the task is showing as a separate task in the task lifetime summary. Is there a way to queue the trace in Instruments into the fact that these are indeed the same task?
1
0
57
3w
How to let instruments - app launch template wait for process to launch , rather than actively launch by instruments
Hi there, How to let instruments - app launch template wait for process to launch , rather than actively launch by instruments? I need to profile the app launch performance when clicking a push notification or cold launch via a url link. How to let instruments to wait for the process and collect the data? Currently, I tried the command xctrace record --template "App Launch" --attach MyApp --device-name 'Phone-Dev' --output mytrace.trace But it soon failed with 'Cannot find process matching name: MyApp'. How to make it work?
0
0
526
Jan ’25
Instruments showing incorrect values
Hello, I’m encountering an issue with the Instruments app while running a benchmark on an M2 Ultra Mac Studio. Despite being certain that GPU activities involving memory read and write operations are occurring, all related performance counters consistently return 0. Interestingly, this problem does not occur when using the same code on an M1 MacBook Air, where the counters behave as expected. What could be causing this discrepancy? Any insights or suggestions would be greatly appreciated. Thank you!
0
0
486
Jan ’25
Configuring "high frequency sampling"
Hey folks, We are looking for a way to increase the sampling frequency beyong what's currently called "high frequency sampling" for CPU profiler (or time profiler -- doesn't really matter for us). We are aware that this is not offered through the UI but wondering if we can somehow experimentally enable this via the .tracetemplate (plist). Basically, we see that samplingRate exists (in the plist) but don't see it having an effect on the actual runs. The resulting trace file always lists sample-rate-micro-seconds="1000" for the data table. E.g., <table trigger="time" pmc-events="Cycles" target-pid="SINGLE" schema="counters-profile" needs-kernel-callstack="0" sample-rate-micro-seconds="1000"/> Cheers
0
0
301
Feb ’25
Understanding power usage on a macOS app
It looks like, for some reason, our apps are using a bunch of power sometimes. sysdiagnose has this in the power log: Never mind. Including the output of sysdiagnose has "sensitive language," and it won't tell me what is sensitive, making this a waste of my time. ETA: Ok, I I can attach the file: power.log I've gone through the energy documentation, but it seems geared towards embedded, not macOS, so I'm not sure how I can figure this out more. The extra problem, of course, is that we have a network extension, two daemons, and a GUI app. 😄
0
0
323
Mar ’25