Microsoft-ui-xaml: Question: how to trace slow UI in a XAML app (e.g. Windows Terminal)

[vadimkantorov]

I have slow reaction (up to 5 seconds) reaction of New Tab buttons in Windows Terminal (context menu takes a few seconds to appear; new tab button freezes for a few seconds before even a new tab is created). I reported the issue in WT repo: https://github.com/microsoft/terminal/issues/6409

I asked how to enable tracing of WT UI handling. I was directed by @zadjii-msft to ask this question in this repo, and @zadjii-msft strongly suggested that the slowness comes not from WT code but from XAML framework itself.

Are there generic ways to trace what is happening? (e.g. what events are emitted and how long do their handling takes). I have zero context about how WT uses XAML or what it does on handling the button clicks. Unfortunately, I don't have experience with using perf.exe or Event Tracing, but I'll be happy to try any instructions you suggest.

My system has about 80% of used physical memory and HDD (it's a L470 lenovo laptop).

[StephenLPeters]

@MikeHillberg @codendone @Austin-Lamb do one of you know the proper route for this question? @vadimkantorov does your performance issue persist even when no debugger is attached to the process? What about release mode?

[vadimkantorov]

I haven't tried attaching debugger to WT. I can try using perf.exe / procmon / Event Tracing / some other tracing if you have some suggestions (I never used them before for perf investigations, I just know they exist).

I think the problem is somehow related to slow disk, and that something is getting loaded from relatively slow HDD. Maybe Windows still swap some pages even though I have 20% memory free as reported by Task Manager, maybe some shared libraries are getting loaded back into memory, maybe some configs are re-read from disk? Maybe some memory compression at fault? After I use these buttons once, they become much faster, so some caching effects are definitely in play.

Ideally it would be good to first get some wall-clock and system-clock timing logs for e.g. button click perceived by XAML and menu drawn/tab created. This should confirm the effect

I assume WT is built in release mode, it's 1.0rc2 version downloaded from Releases, I didn't compile it myself. I'll upgrade it to 1.0 release, just in case.

[vadimkantorov]

I've done a quick perfmon run on "fast" speed of just showing the New Tab menu, and I see a lot of language/i18n-related registry operations, some font loads and some pagefile reads. Probably Windows swaps things to disk even though WT has 7mb working set (reported by Task Manager).

A question is: why is there a pagefile read to just show a menu?

I'll do a similar run for on "slow" speed as well

Pagefile read details are:

Offset: 9,828,593,664, Length: 32,768, I/O Flags: Non-cached, Paging I/O, Synchronous Paging I/O, Priority: Normal

it's only a 32k read - probably a slow one, I wish it could be avoided

[vadimkantorov]

I did two "slow" procmon traces and attach them in native procmon format inside the zip.

They confirm that the problem is loading from pagefile.sys. The question is: can you figure out what is it loading from pagefile.sys? It seems that it's just the app DLLs. Do you see some other things?

procmon_traces.zip

Process Explorer shows that WT uses a lot of dynamic shared libraries including a dozen XAML ones. Procexp shows that real WorkingSet is around 65Mb and PrivateBytes 250Mb (just one open tab inside Terminal).

Should we just ask WT to reduce WorkingSet and used shared libraries / fonts? Does XAML framework have some guidelines for apps to follow that want to minimize resource usage?

Process: WindowsTerminal.exe Pid: 992

Name    Description Company Name    Path
{6AF0698E-D558-4F6E-9B3C-3716689AF493}.2.ver0x0000000000000002.db           C:\ProgramData\Microsoft\Windows\Caches\{6AF0698E-D558-4F6E-9B3C-3716689AF493}.2.ver0x0000000000000002.db
{AFBF9F1A-8EE8-4C77-AF34-C647E37CA0D9}.1.ver0x0000000000000005.db           C:\Users\user\AppData\Local\Microsoft\Windows\Caches\{AFBF9F1A-8EE8-4C77-AF34-C647E37CA0D9}.1.ver0x0000000000000005.db
{DDF571F2-BE98-426D-8288-1A9A39C3FDA2}.2.ver0x0000000000000002.db           C:\ProgramData\Microsoft\Windows\Caches\{DDF571F2-BE98-426D-8288-1A9A39C3FDA2}.2.ver0x0000000000000002.db
~FontCache-FontFace.dat         C:\Windows\ServiceProfiles\LocalService\AppData\Local\FontCache\~FontCache-FontFace.dat
~FontCache-S-1-5-21-111876015-96469450-1807641949-1001.dat          C:\Windows\ServiceProfiles\LocalService\AppData\Local\FontCache\~FontCache-S-1-5-21-111876015-96469450-1807641949-1001.dat
advapi32.dll    Advanced Windows 32 Base API    Microsoft Corporation   C:\Windows\System32\advapi32.dll
avrt.dll    Multimedia Realtime Runtime Microsoft Corporation   C:\Windows\System32\avrt.dll
BCP47Langs.dll  BCP47 Language Classes  Microsoft Corporation   C:\Windows\System32\BCP47Langs.dll
BCP47mrm.dll    BCP47 Language Classes for Resource Management  Microsoft Corporation   C:\Windows\System32\BCP47mrm.dll
bcrypt.dll  Windows Cryptographic Primitives Library    Microsoft Corporation   C:\Windows\System32\bcrypt.dll
bcryptprimitives.dll    Windows Cryptographic Primitives Library    Microsoft Corporation   C:\Windows\System32\bcryptprimitives.dll
capauthz.dll    Capability Authorization APIs   Microsoft Corporation   C:\Windows\System32\capauthz.dll
CascadiaMono.ttf            C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\CascadiaMono.ttf
cfgmgr32.dll    Configuration Manager DLL   Microsoft Corporation   C:\Windows\System32\cfgmgr32.dll
clbcatq.dll COM+ Configuration Catalog  Microsoft Corporation   C:\Windows\System32\clbcatq.dll
cldapi.dll  Cloud API user mode API Microsoft Corporation   C:\Windows\System32\cldapi.dll
combase.dll Microsoft COM for Windows   Microsoft Corporation   C:\Windows\System32\combase.dll
comctl32.dll    User Experience Controls Library    Microsoft Corporation   C:\Windows\WinSxS\amd64_microsoft.windows.common-controls_6595b64144ccf1df_6.0.18362.836_none_e6c4b943130f18ed\comctl32.dll
coml2.dll   Microsoft COM for Windows   Microsoft Corporation   C:\Windows\System32\coml2.dll
concrt140.dll   Microsoft® Concurrency Runtime Library  Microsoft Corporation   C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\concrt140.dll
concrt140_app.dll           C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\concrt140_app.dll
container.dll   Windows Containers  Microsoft Corporation   C:\Windows\System32\container.dll
CoreMessaging.dll   Microsoft CoreMessaging Dll Microsoft Corporation   C:\Windows\System32\CoreMessaging.dll
CoreUIComponents.dll    Microsoft Core UI Components Dll    Microsoft Corporation   C:\Windows\System32\CoreUIComponents.dll
cpprest142_2_10.dll         C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\cpprest142_2_10.dll
crypt32.dll Crypto API32    Microsoft Corporation   C:\Windows\System32\crypt32.dll
cryptbase.dll   Base cryptographic API DLL  Microsoft Corporation   C:\Windows\System32\cryptbase.dll
cryptsp.dll Cryptographic Service Provider API  Microsoft Corporation   C:\Windows\System32\cryptsp.dll
cversions.2.db          C:\ProgramData\Microsoft\Windows\Caches\cversions.2.db
cversions.2.db          C:\ProgramData\Microsoft\Windows\Caches\cversions.2.db
d2d1.dll    Microsoft D2D Library   Microsoft Corporation   C:\Windows\System32\d2d1.dll
d3d11.dll   Direct3D 11 Runtime Microsoft Corporation   C:\Windows\System32\d3d11.dll
D3DCompiler_47.dll  Direct3D HLSL Compiler  Microsoft Corporation   C:\Windows\System32\D3DCompiler_47.dll
DataExchange.dll    Data exchange   Microsoft Corporation   C:\Windows\System32\DataExchange.dll
daxexec.dll daxexec Microsoft Corporation   C:\Windows\System32\daxexec.dll
dcomp.dll   Microsoft DirectComposition Library Microsoft Corporation   C:\Windows\System32\dcomp.dll
directmanipulation.dll  Microsoft Direct Manipulation Component Microsoft Corporation   C:\Windows\System32\directmanipulation.dll
dpapi.dll   Data Protection API Microsoft Corporation   C:\Windows\System32\dpapi.dll
dwmapi.dll  Microsoft Desktop Window Manager API    Microsoft Corporation   C:\Windows\System32\dwmapi.dll
DWrite.dll  Microsoft DirectX Typography Services   Microsoft Corporation   C:\Windows\System32\DWrite.dll
DXCore.dll  DXCore  Microsoft Corporation   C:\Windows\System32\DXCore.dll
dxgi.dll    DirectX Graphics Infrastructure Microsoft Corporation   C:\Windows\System32\dxgi.dll
edputil.dll EDP util    Microsoft Corporation   C:\Windows\System32\edputil.dll
fltLib.dll  Filter Library  Microsoft Corporation   C:\Windows\System32\fltLib.dll
FontCache-Obsolete-828.dat          C:\Windows\ServiceProfiles\LocalService\AppData\Local\FontCache\FontCache-Obsolete-828.dat
gdi32.dll   GDI Client DLL  Microsoft Corporation   C:\Windows\System32\gdi32.dll
gdi32full.dll   GDI Client DLL  Microsoft Corporation   C:\Windows\System32\gdi32full.dll
iertutil.dll    Run time utility for Internet Explorer  Microsoft Corporation   C:\Windows\System32\iertutil.dll
igc64.dll   Intel Graphics Shader Compiler for Intel(R) Graphics Accelerator    Intel Corporation   C:\Windows\System32\DriverStore\FileRepository\igdlh64.inf_amd64_77aa8b07b10eaefc\igc64.dll
igd10iumd64.dll User Mode Driver for Intel(R) Graphics Technology   Intel Corporation   C:\Windows\System32\DriverStore\FileRepository\igdlh64.inf_amd64_77aa8b07b10eaefc\igd10iumd64.dll
imm32.dll   Multi-User Windows IMM32 API Client DLL Microsoft Corporation   C:\Windows\System32\imm32.dll
InputHost.dll   InputHost   Microsoft Corporation   C:\Windows\System32\InputHost.dll
IPHLPAPI.DLL    IP Helper API   Microsoft Corporation   C:\Windows\System32\IPHLPAPI.DLL
kernel.appcore.dll  AppModel API Host   Microsoft Corporation   C:\Windows\System32\kernel.appcore.dll
kernel32.dll    Windows NT BASE API Client DLL  Microsoft Corporation   C:\Windows\System32\kernel32.dll
KernelBase.dll  Windows NT BASE API Client DLL  Microsoft Corporation   C:\Windows\System32\KernelBase.dll
KernelBase.dll.mui  Windows NT BASE API Client DLL  Microsoft Corporation   C:\Program Files\WindowsApps\Microsoft.LanguageExperiencePacken-US_18362.14.15.0_neutral__8wekyb3d8bbwe\Windows\System32\en-US\KernelBase.dll.mui
locale.nls          C:\Windows\System32\locale.nls
Microsoft.Toolkit.Win32.UI.XamlHost.dll         C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\Microsoft.Toolkit.Win32.UI.XamlHost.dll
Microsoft.UI.Xaml.dll   Microsoft.UI.Xaml.dll   Microsoft Corporation   C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\Microsoft.UI.Xaml.dll
mlang.dll   Multi Language Support DLL  Microsoft Corporation   C:\Windows\System32\mlang.dll
mpr.dll Multiple Provider Router DLL    Microsoft Corporation   C:\Windows\System32\mpr.dll
MrmCoreR.dll    Microsoft Windows MRM   Microsoft Corporation   C:\Windows\System32\MrmCoreR.dll
msasn1.dll  ASN.1 Runtime APIs  Microsoft Corporation   C:\Windows\System32\msasn1.dll
msctf.dll   MSCTF Server DLL    Microsoft Corporation   C:\Windows\System32\msctf.dll
msvcp_win.dll   Microsoft® C Runtime Library    Microsoft Corporation   C:\Windows\System32\msvcp_win.dll
msvcp110_win.dll    Microsoft® STL110 C++ Runtime Library   Microsoft Corporation   C:\Windows\System32\msvcp110_win.dll
msvcp140.dll    Microsoft® C Runtime Library    Microsoft Corporation   C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\msvcp140.dll
msvcp140_app.dll            C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\msvcp140_app.dll
msvcrt.dll  Windows NT CRT DLL  Microsoft Corporation   C:\Windows\System32\msvcrt.dll
ncrypt.dll  Windows NCrypt Router   Microsoft Corporation   C:\Windows\System32\ncrypt.dll
ninput.dll  Microsoft Pen and Touch Input Component Microsoft Corporation   C:\Windows\System32\ninput.dll
NoiseAsset_256X256_PNG.png          C:\Program Files\WindowsApps\Microsoft.WindowsStore_12005.1001.1.0_x64__8wekyb3d8bbwe\Microsoft.UI.Xaml\Assets\NoiseAsset_256X256_PNG.png
ntasn1.dll  Microsoft ASN.1 API Microsoft Corporation   C:\Windows\System32\ntasn1.dll
ntdll.dll   NT Layer DLL    Microsoft Corporation   C:\Windows\System32\ntdll.dll
ntmarta.dll Windows NT MARTA provider   Microsoft Corporation   C:\Windows\System32\ntmarta.dll
ole32.dll   Microsoft OLE for Windows   Microsoft Corporation   C:\Windows\System32\ole32.dll
oleaut32.dll    OLEAUT32.DLL    Microsoft Corporation   C:\Windows\System32\oleaut32.dll
OneCoreUAPCommonProxyStub.dll   OneCoreUAP Common Proxy Stub    Microsoft Corporation   C:\Windows\System32\OneCoreUAPCommonProxyStub.dll
pcacli.dll  Program Compatibility Assistant Client Module   Microsoft Corporation   C:\Windows\System32\pcacli.dll
pdh.dll Windows Performance Data Helper DLL Microsoft Corporation   C:\Windows\System32\pdh.dll
policymanager.dll   Policy Manager DLL  Microsoft Corporation   C:\Windows\System32\policymanager.dll
powrprof.dll    Power Profile Helper DLL    Microsoft Corporation   C:\Windows\System32\powrprof.dll
profapi.dll User Profile Basic API  Microsoft Corporation   C:\Windows\System32\profapi.dll
profext.dll profext Microsoft Corporation   C:\Windows\System32\profext.dll
propsys.dll Microsoft Property System   Microsoft Corporation   C:\Windows\System32\propsys.dll
resources.pri           C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\resources.pri
rmclient.dll    Resource Manager Client Microsoft Corporation   C:\Windows\System32\rmclient.dll
rometadata.dll  Microsoft MetaData Library  Microsoft Corporation   C:\Windows\System32\rometadata.dll
rpcrt4.dll  Remote Procedure Call Runtime   Microsoft Corporation   C:\Windows\System32\rpcrt4.dll
sechost.dll Host for SCM/SDDL/LSA Lookup APIs   Microsoft Corporation   C:\Windows\System32\sechost.dll
secur32.dll Security Support Provider Interface Microsoft Corporation   C:\Windows\System32\secur32.dll
segoeui.ttf         C:\Windows\Fonts\segoeui.ttf
segoeuib.ttf            C:\Windows\Fonts\segoeuib.ttf
setupapi.dll    Windows Setup API   Microsoft Corporation   C:\Windows\System32\setupapi.dll
sfc_os.dll  Windows File Protection Microsoft Corporation   C:\Windows\System32\sfc_os.dll
SHCore.dll  SHCORE  Microsoft Corporation   C:\Windows\System32\SHCore.dll
shell32.dll Windows Shell Common Dll    Microsoft Corporation   C:\Windows\System32\shell32.dll
shlwapi.dll Shell Light-weight Utility Library  Microsoft Corporation   C:\Windows\System32\shlwapi.dll
SortDefault.nls         C:\Windows\Globalization\Sorting\SortDefault.nls
sspicli.dll Security Support Provider Interface Microsoft Corporation   C:\Windows\System32\sspicli.dll
StaticCache.dat         C:\Windows\Fonts\StaticCache.dat
sxs.dll Fusion 2.5  Microsoft Corporation   C:\Windows\System32\sxs.dll
telnetpp.dll            C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\telnetpp.dll
TerminalApp.dll         C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\TerminalApp.dll
TerminalConnection.dll          C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\TerminalConnection.dll
TerminalControl.dll         C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\TerminalControl.dll
TerminalSettings.dll            C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\TerminalSettings.dll
TerminalThemeHelpers.dll            C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\TerminalThemeHelpers.dll
TextInputFramework.dll  "TextInputFramework.DYNLINK"    Microsoft Corporation   C:\Windows\System32\TextInputFramework.dll
threadpoolwinrt.dll Windows WinRT Threadpool    Microsoft Corporation   C:\Windows\System32\threadpoolwinrt.dll
twinapi.appcore.dll twinapi.appcore Microsoft Corporation   C:\Windows\System32\twinapi.appcore.dll
twinapi.dll twinapi Microsoft Corporation   C:\Windows\System32\twinapi.dll
twinui.appcore.dll  TWINUI.APPCORE  Microsoft Corporation   C:\Windows\System32\twinui.appcore.dll
twinui.dll  TWINUI  Microsoft Corporation   C:\Windows\System32\twinui.dll
ucrtbase.dll    Microsoft® C Runtime Library    Microsoft Corporation   C:\Windows\System32\ucrtbase.dll
UiaManager.dll  UiaManager  Microsoft Corporation   C:\Windows\System32\UiaManager.dll
UIAutomationCore.dll    Microsoft UI Automation Core    Microsoft Corporation   C:\Windows\System32\UIAutomationCore.dll
umpdc.dll           C:\Windows\System32\umpdc.dll
urlmon.dll  OLE32 Extensions for Win32  Microsoft Corporation   C:\Windows\System32\urlmon.dll
user32.dll  Multi-User Windows USER API Client DLL  Microsoft Corporation   C:\Windows\System32\user32.dll
userenv.dll Userenv Microsoft Corporation   C:\Windows\System32\userenv.dll
uxtheme.dll Microsoft UxTheme Library   Microsoft Corporation   C:\Windows\System32\uxtheme.dll
vccorlib140.dll Microsoft ® VC WinRT core library   Microsoft Corporation   C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\vccorlib140.dll
vccorlib140_app.dll         C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\vccorlib140_app.dll
vcruntime140.dll    Microsoft® C Runtime Library    Microsoft Corporation   C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\vcruntime140.dll
vcruntime140_1.dll  Microsoft® C Runtime Library    Microsoft Corporation   C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\vcruntime140_1.dll
vcruntime140_1_app.dll          C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\vcruntime140_1_app.dll
vcruntime140_app.dll            C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\vcruntime140_app.dll
win32u.dll  Win32u  Microsoft Corporation   C:\Windows\System32\win32u.dll
windows.applicationmodel.datatransfer.dll   Windows.ApplicationModel.DataTransfer   Microsoft Corporation   C:\Windows\System32\windows.applicationmodel.datatransfer.dll
Windows.ApplicationModel.dll    Windows ApplicationModel API Server Microsoft Corporation   C:\Windows\System32\Windows.ApplicationModel.dll
Windows.Energy.dll  Windows Energy Runtime DLL  Microsoft Corporation   C:\Windows\System32\Windows.Energy.dll
Windows.Globalization.dll   Windows Globalization   Microsoft Corporation   C:\Windows\System32\Windows.Globalization.dll
Windows.Graphics.dll    WinRT Windows Graphics DLL  Microsoft Corporation   C:\Windows\System32\Windows.Graphics.dll
Windows.StateRepositoryCore.dll Windows StateRepository API Core    Microsoft Corporation   C:\Windows\System32\Windows.StateRepositoryCore.dll
windows.storage.dll Microsoft WinRT Storage API Microsoft Corporation   C:\Windows\System32\windows.storage.dll
windows.storage.dll.mui Microsoft WinRT Storage API Microsoft Corporation   C:\Program Files\WindowsApps\Microsoft.LanguageExperiencePacken-US_18362.14.15.0_neutral__8wekyb3d8bbwe\Windows\System32\en-US\windows.storage.dll.mui
Windows.System.Launcher.dll Windows.System.Launcher Microsoft Corporation   C:\Windows\System32\Windows.System.Launcher.dll
Windows.UI.Core.TextInput.dll   Windows.UI.Core.TextInput dll   Microsoft Corporation   C:\Windows\System32\Windows.UI.Core.TextInput.dll
Windows.UI.dll  Windows Runtime UI Foundation DLL   Microsoft Corporation   C:\Windows\System32\Windows.UI.dll
Windows.UI.dll.mui  Windows Runtime UI Foundation DLL   Microsoft Corporation   C:\Program Files\WindowsApps\Microsoft.LanguageExperiencePacken-US_18362.14.15.0_neutral__8wekyb3d8bbwe\Windows\System32\en-US\Windows.UI.dll.mui
Windows.UI.Immersive.dll    WINDOWS.UI.IMMERSIVE    Microsoft Corporation   C:\Windows\System32\Windows.UI.Immersive.dll
Windows.UI.winmd    Windows SDK metadata    Microsoft Corporation   C:\Windows\System32\WinMetadata\Windows.UI.winmd
Windows.UI.Xaml.Controls.dll    Windows.UI.Xaml.Controls    Microsoft Corporation   C:\Windows\System32\Windows.UI.Xaml.Controls.dll
Windows.UI.Xaml.Controls.dll    Windows.UI.Xaml.Controls    Microsoft Corporation   C:\Windows\System32\Windows.UI.Xaml.Controls.dll
Windows.UI.Xaml.dll Windows.UI.Xaml dll Microsoft Corporation   C:\Windows\System32\Windows.UI.Xaml.dll
windows.ui.xaml.dll.mui Windows.UI.Xaml dll Microsoft Corporation   C:\Program Files\WindowsApps\Microsoft.LanguageExperiencePacken-US_18362.14.15.0_neutral__8wekyb3d8bbwe\Windows\System32\en-US\windows.ui.xaml.dll.mui
Windows.UI.Xaml.InkControls.dll Windows UI XAML InkControls API Microsoft Corporation   C:\Windows\System32\Windows.UI.Xaml.InkControls.dll
Windows.UI.Xaml.Maps.dll    Windows UI XAML Maps API    Microsoft Corporation   C:\Windows\System32\Windows.UI.Xaml.Maps.dll
Windows.UI.Xaml.Phone.dll   Windows UI XAML Phone API   Microsoft Corporation   C:\Windows\System32\Windows.UI.Xaml.Phone.dll
Windows.UI.Xaml.Resources.19h1.dll  Windows.UI.Xaml.Resources.19H1 dll  Microsoft Corporation   C:\Windows\System32\Windows.UI.Xaml.Resources.19h1.dll
Windows.UI.Xaml.Resources.Common.dll    Windows.UI.Xaml.Resources.Common.dll    Microsoft Corporation   C:\Windows\System32\Windows.UI.Xaml.Resources.Common.dll
Windows.UI.Xaml.winmd   Windows SDK metadata    Microsoft Corporation   C:\Windows\System32\WinMetadata\Windows.UI.Xaml.winmd
WindowsCodecs.dll   Microsoft Windows Codecs Library    Microsoft Corporation   C:\Windows\System32\WindowsCodecs.dll
WindowsTerminal.exe         C:\Program Files\WindowsApps\Microsoft.WindowsTerminal_0.11.1333.0_x64__8wekyb3d8bbwe\WindowsTerminal.exe
wininet.dll Internet Extensions for Win32   Microsoft Corporation   C:\Windows\System32\wininet.dll
wintrust.dll    Microsoft Trust Verification APIs   Microsoft Corporation   C:\Windows\System32\wintrust.dll
WinTypes.dll    Windows Base Types DLL  Microsoft Corporation   C:\Windows\System32\WinTypes.dll
wuceffects.dll  Microsoft Composition Effects   Microsoft Corporation   C:\Windows\System32\wuceffects.dll

[weltkante]

My system has about 80% of used physical memory

Its usually bad to let used physical memory get such high because it leaves too little room for file caching. That means Windows has more often to take the significantly slower path to the disk instead of reading from caches. Depending on what you do you want a few GB of unused memory for file caching.

A question is: why is there a pagefile read to just show a menu?

Windows backs (almost) everyhing by the pagefile, this is necessary because it is overcommitting memory, allowing you to run more applications than you actually have memory for, knowing that most application will not be using all the memory they reserved.

It is normal that with high physical memory load Windows will swap out currently unused memory and swap it back in when its used again. This means with higher memory load you get more disk access and generally things become slower, long before you actually hit "out of memory" errors.

Try the RamMap tool from sysinternals and "Empty Working Sets" - it forces to flush out memory from currently unused applications when Windows isn't doing its job good enough, leaving more space for file caches etc. It helps a lot for my 8 GB notebook, without manually flushing from time to time my notebook starts swapping (and slowing down) like crazy.

If that helps you are just observing your machine approaching the out of memory barrier, and Windows trying to keep the system responsive by doing more swapping, which ironically reduces responsiveness. I think the OS heuristics for the pagefile have been tuned for more modern machines, thats probably why the slowdown on older ones with less RAM are so exaggerated.

PS: just commenting based on research I did on my own notebook slowdowns, may or may not be related to yours

[vadimkantorov]

@weltkante RAMMap "Empty *" seems to have helped considerably

[weltkante]

Then its probably an OS level issue and its unlikely WinUI by itself can do much about it, not sure what the appropriate way is to handle this, lets wait for a response from the team.

I fully agree that the OS should handle older hardware with limited RAM better, you shouldn't have to do a manually forced flush to get a responsive system.

[vadimkantorov]

@welkante I wonder if XAML controls could benefit from IL linker / symbol trimming in general

[vadimkantorov]

@StephenLPeters I think a summary for my asks of WinRT / XAML / WinUI side would be:

1) easy tracing ways to measure responsiveness of UI

2) advice on measuring perf, including measuring working set, inducing Windows to low-memory mode (probably easily done with a VM, but maybe other simpler ways exist), counting page faults, waiting on accessing memory because of memory compression, not getting CPU time because of low-pri / being blocked on UI thread waiting for sth, et cetera

3) advice for apps on how to reduce working set. is there some linker that can strip unused controls from the dll? why is xaml.maps / xaml.phone getting loaded in Terminal that has nothing to do with them?

Terminal by itself is not very keen on doing these investigations, reason being roughly "we are not doing anything special, so it perf should be fixed upstream so that everyone benefits" (speaking from my original issue in the repo)

[StephenLPeters]

I think @Austin-Lamb @MikeHillberg or @codendone would have more context or be able to point to someone who does. Could one of you weigh in here?

[ranjeshj]

@bartekk8 as FYI

[bartekk8]

Hello,

Let's start with getting a trace of your sceanrio. To trace XAML app, follow these steps:

1. Install ADK (https://docs.microsoft.com/en-us/windows-hardware/get-started/adk-install). You only need Windows Performance Toolkit option to be selected.
   
   
   
   • more details: https://docs.microsoft.com/en-us/windows-hardware/test/wpt/windows-performance-recorder
   
   
2. Execute wprui.exe (Windows Performance Recorder).
3. The default profile options should provide enough information about what's going on in the system / app. Click on Start.
4. Run your scenario.
5. Click Save and follow the prompts. If you'd like to look at the trace right away, after it's saved click on Open in WPA.
6. WPA is a great tool for analyzing traces. For intro on how to use it take a look here: https://docs.microsoft.com/en-us/windows-hardware/test/wpt/windows-performance-analyzer

I hope this helps!

[vadimkantorov]

I kind of confirmed it’s low memory / swapping that is the problem. And I could see in the procmon taking time to load libraries from disk. When I have more memory available, Terminal works faster.

Speaking more generally, it would be great if these tools could be easily installed from Store or shipped with windows. Having perf kit shipped only with adk seems s big stumbling part.

Ideally, there would be some library that a client app like Terminal could use to do some trace of perf, and e.g. use it in Telemetry or in issue reports.

Questions about libraries and reducing working set / linker still hold.

Also maybe this issue should be moved to https://github.com/microsoft/ProjectReunion, please feel free to move it if it better fits there :)

[vadimkantorov]

One example that would also benefit from super-easy perf recording (by non windev-experienced end users) is slow Calculator start-up https://github.com/microsoft/calculator/issues/209

[trgibeau]

Hi @vadimkantorov,

For your comment:

Speaking more generally, it would be great if these tools could be easily installed from Store or shipped with windows. Having perf kit shipped only with adk seems s big stumbling part.

If your running Windows 10;

• Windows Performance Analyzer (WPA) is now available directly from the store:
  https://www.microsoft.com/en-us/p/windows-performance-analyzer/9n0w1b2bxgnz?activetab=pivot:overviewtab

• Windows Performance Recorder (WPR) command line is "inbox", here is how to use the command line:
  https://docs.microsoft.com/en-us/windows-hardware/test/wpt/wpr-command-line-options

Hopefully these can get you started without the ADK.

[vadimkantorov]

Thanks for advice about WPA. I'll try it next time! Unfortunately, these are "advanced" tools enough so that Microsoft Terminal devs sent me to this repo and suggested asking a question as an issue here. Maybe they are not accustomed to using these tools either :( They didn't communicate to me any prior attempts to measure Working Set memory or number of used shared libraries or testing the app in low-memory conditions and continued to refer that I should investigate this myself (with your help) in this repo :(

The general questions about "why Terminal (that uses winrt/winui?)" uses so many assemblies and if it can make use of some linker to strip unused controls holds.

[zadjii-msft]

For the record, the Terminal team is plenty accustomed to using those tools, we've just focused our efforts primarily on CPU performance, because the memory impact of the actual _terminal_ bits of the Terminal is pretty minimal. We've kicked this thread over to the WinUI repo because the people who are best equipped to analyze the memory impact of WinUI are _the people who own WinUI_.

[vadimkantorov]

On my side, I'll incur my machine in low-memory mode and will provide you a wprp file.

About tools / WinUI: even a simple procmon run sufficed to find low-memory / swapping problems. And procexp.exe showed the problem of a lot of (seemingly unrelated) shared libraries. If you had adviced directly to download WPA (also completely generic, not WinUI-specific) from windows store and how to configure it to run on Terminal, I would have tried to use it from the get-go.

@zadjii-msft Sorry for a lot of mis-communication.

[vadimkantorov]

Maybe this issue now would be better transferred to https://github.com/microsoft/windev (as per too many libraries used by winrt and for optimizing down the working set of winrt/winui apps including Terminal)

[zadjii-msft]

IMO It would probably just get punted back to the experts over here, or to Kenny over in microsoft/xlang / microsoft/cppwinrt, but I doubt the language itself is at fault here - I'd imagine that those libraries are getting regardless if XAML is being used via c++/winrt, c#, rust, cxx, or whatever other language the xlang team adds WinRT support to next.