Hey,
In the UI of the Instruments app, I can change the recording mode to immediate. Is that possible when using xctrace? It seems to use deferred as a default.
I've tried to create a template, set the recording mode to immediate, and use that template for recording. However, that doesn't seem to work. At least the exported TOC of the .trace will have the following summary:
<summary>
<start-date>2025-01-11T13:00:11.365+01:00</start-date>
<end-date>2025-01-11T13:00:30.525+01:00</end-date>
<duration>19.160279</duration>
<end-reason>Target app exited</end-reason>
<instruments-version>16.0 (16A242d)</instruments-version>
<template-name>core_animation_fps</template-name>
<recording-mode>Deferred</recording-mode>
<time-limit>12 hours</time-limit>
</summary>
This issue might be related to: https://developer.apple.com/forums/thread/735948
Thanks a lot!
Instruments
RSS for tagInstruments is a performance-analysis and testing tool for iOS, iPadOS, watchOS, tvOS, and macOS apps.
Selecting any option will automatically load the page
Post
Replies
Boosts
Views
Activity
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?
Topic:
Developer Tools & Services
SubTopic:
Instruments
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!
Topic:
Developer Tools & Services
SubTopic:
Instruments
Tags:
Metal
Metal Performance Shaders
metal-cpp
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
Topic:
Developer Tools & Services
SubTopic:
Instruments
* [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.)
Topic:
Developer Tools & Services
SubTopic:
Instruments
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. 😄
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.
I am using XCode16 and macOS 14.7.2. Previously, using the instruments on an iPhone with iOS 14.3 was normal, but when I upgraded to iOS 18, the instruments often couldn't find the library.
I have to restart the instruments to restore normal operation, but the problem will occur again after using it for a period of time
Context
I created a short script to CPU profile a program from the command line. I am able to record via the Instruments app, but when I try from the command line I get the following error shown below. This example is just profiling the grep command.
Error:
% cpu_profile /usr/bin/grep \
--recursive "Brendan Gregg" \
"$(xcode-select --print-path)/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk"
Profiling /usr/bin/grep into /tmp/cpu_profile_grep.trace
Starting recording with the CPU Profiler template. Launching process: grep.
Ctrl-C to stop the recording
Run issues were detected (trace is still ready to be viewed):
* [Error] Failed to start the recording: Failed to force all hardware CPU counters: 13.
Recording failed with errors. Saving output file...
Script:
#!/bin/sh
set -o errexit
set -o nounset
if [ "$#" -lt 1 ]
then
echo "Usage $0 <program> [arguments...]" 1>&2
exit 1
fi
PROGRAM="$(realpath "$1")"
shift
OUTPUT="/tmp/cpu_profile_$(basename "$PROGRAM").trace"
echo "Profiling $PROGRAM into $OUTPUT" 1>&2
# Delete potential previous traces
rm -rf "$OUTPUT"
xcrun xctrace record \
--template 'CPU Profiler' \
--no-prompt \
--output "$OUTPUT" \
--target-stdout - \
--launch -- "$PROGRAM" "$@"
open "$OUTPUT"
I think the error has to do with xctrace based on this post, but according to this post it should have been resolved in MacOS version 15.4.
System
Chip: Apple M3 Pro
macOS: Sequoia 15.4.1
xctrace version: 16.0 (16E140)
xcrun version: 70.
Xcode version: 16.3 (16E140)
Working Screenshots from Instruments App:
Topic:
Developer Tools & Services
SubTopic:
Instruments
Tags:
Developer Tools
Instruments
Xcode
Debugging
I want to check the disassembly code of vImage function by Instrument.
But when I double click the stack of time profiler, I can see nothing.
My Mac is intel chip and iPhone is 14 pro max
Xcode version is 16.3.
How can I fix this(maybe no .dSYM in iOS device support?)
I am trying to record the requests and responses in a WKWebView, but instruments does not seem to record them. Is this to be expected?
The webView is set to inspectable, and I am using the HTTP Traffic instrument.
All the requests the app is doing are recorded, but neither the original request for the webView, nor subsequent traffic is recorded.
When I use Safari to inspect the webView, all I see is the last page (even when I start the inspector before the first request is made).
How can I see these requests?
I made a box with MDLMesh.newBox(). I added normals.
let mdlMesh = MDLMesh.newBox(withDimensions: SIMD3<Float>(1, 1, 1),
segments: SIMD3<UInt32>(2, 2, 2),
geometryType: MDLGeometryType.triangles,
inwardNormals:false,
allocator: allocator)
mdlMesh.addNormals(withAttributeNamed: MDLVertexAttributeNormal, creaseThreshold: 0.25)
After I convert to MTKMesh the normals are (0,0,0) for a group of vertices. I can only inspect the geometry after I convert to MTKMesh. Is there a way you can use Geometry Viewer on a MDLMesh?
hello, I got a question about coreml.
I loaded the coreml model in the project and set the computing unit to CPU+GPU.
When I used instruments to analyze the performance, I found that there was an overhead of prepare gpu request before each inference. I also checked the freezing point graph and found that memory was frequently allocated.
Is this as expected? Is there any way to avoid frequent prepares?
I have tried some methods, such as memory sharing of predict interface input parameters, but it seems to be ineffective.
Hi, I need help to get Instruments running to profile my application. I tried to profile my main app (Qt-5.15-Framework, c++, Intel-arch only) from Xcode. My app starts and Instruments runs time profiler or Leaks for about 15 seconds and the quits. No crash, no message nothing.
This has been happening for a while on my Mac Studio M1 Max running macOS 14.7.6 and Xcode 15.4 IDE with a toolchain from Xcode 14.3 for the qmake (qt) project. However, this also happens if i set up a new vanilla Swift UI project from scratch wihtout any Qt stuff.
In addition to the Mac Studio I also have Mac Book Pro M4 running macOS 15.5 and Xcode 16.4. On that machine I get the same results, no matter if I try Instruments on my qt project or a vanilla SwiftUI project.
Also it does not make a difference if I change the toolchain with:
sudo xcode-select -s /Applications/Xcode_143.app
or
sudo xcode-select -s /Applications/Xcode_164.app.
Same results in either case.
I also tried switching to Debug build in the editing the scheme for profiling, but got no better results.
I also tried to lauch Instruments from Xcode using the Open Developer Tool menu entry, but got no better results.
When I start Instruments first, run my program in Xcode and attach to it, I get the same results.
Do you have any advice what to check for or to setup, maybe in signing or such? I am probably missing something basic.
Thanks in advance
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.
Instruments: GPU Service reported error: Selected counter profile is not supported on target device`
I could use the Metal System Trace before the most recent update, but now whenever I try to profile using the Metal Counter instrument, I get the
[Warning] GPU Service reported error: Selected counter profile is not supported on target device. What is the issue here?
It seems as though using any initializer of SubscriptionOfferView or StoreView will create a memory leak.
This can be simply reproduced by adding this to your SwiftUI view:
SubscriptionOfferView(groupID: "yourgroupID", visibleRelationship: .all, useAppIcon: true)
or
StoreView(ids: ["monthly", "yearly"])
Tested on iOS 26 beta 2
Dear Apple Developer Support team,
I would like to request an official confirmation regarding the handling of transaction status in the App Store Server API, specifically for the GET /inApps/v1/transactions/{transactionId} endpoint.
As per our current understanding from the official documentation (Get Transaction Info), the API’s behavior appears to be:
If a transaction is finalized and successfully processed by App Store, querying this API will return HTTP 200 OK along with transaction details.
If a transaction is still in a pending or deferred state (such as awaiting Ask to Buy approval or pending authorization), the API will not return a 200, and instead respond with HTTP 404 Not Found or an appropriate error.
Could you please confirm if this behavior is accurate and officially supported?
Specifically:
Does a 200 OK response guarantee that a transaction is finalized and successfully recorded on App Store servers?
In cases where a transaction is pending approval (e.g. Ask to Buy), is it correct that GET /transactions/{transactionId} would return 404 Not Found until the transaction is finalized?
We would greatly appreciate your confirmation to align our server-side logic for transaction validation accordingly.
Thank you very much for your support!
Kind regards,
cuongnx
Topic:
Developer Tools & Services
SubTopic:
Instruments
Tags:
Wallet
StoreKit Test
StoreKit
Apple Pay
Hi,
My name is Hani Nemati, and I work at Microsoft, where we support several macOS applications such as Microsoft Edge and Teams. I’m also the primary contributor to Microsoft Performance Tools for Apple (https://github.com/microsoft/Microsoft-Performance-Tools-Apple), an open-source project aimed at improving trace analysis across platforms.
We are exploring ways to enhance our performance tracing capabilities on macOS and are particularly interested in the ability to attach PMU (Performance Monitoring Unit) counters to context switch events during trace collection. For reference, this capability is supported on Linux via LTTng using the add-context option (https://lttng.org/man/1/lttng-add-context/v2.13), and on Windows through Windows Performance Recorder (WPR), which allows PMU counters to be added at the start and end of context switches, enabling delta computation.
Would it be possible to introduce similar support in Instruments for macOS?
I’d appreciate any guidance or suggestions you might have on this request.
Thank you,
Hani Nemati
Email: hanemati@microsoft
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
Topic:
Developer Tools & Services
SubTopic:
Instruments