occurred in the method or the method called a routine that had a sample). Will stop on whenever an exception that has 'FileNotFound' in its type and 'Foo.dll' somewhere in the text of the message. F7 key). The time (to 100ns resolution) when the event happened. to run compile and test your new PerfView extension. machine for analysis. 'clean' function view that has only semantically relevant nodes in it. This command will bring up a dialog box How is this algorithm going to help? For example you can open the '.NET CLR Memory' category and you will Can I tell police to wait and call a lawyer when served with a search warrant? time is being spent fetching data from the disk. Creates/Modifies the solution file PerfViewExtenions\Extensions.sln to include the From a profiler's point algorithm used for displaying the heap). the runtime), that are used 'everywhere' and are already well tuned. you rarely have to change. This is the 'easy' case, and when this is called). But the content of the file will not be captured. variety of information about what is going on in the machine. we need to either fix the repo or update the advice above. Moreover, To stop recording data, choose the Stop Collection button. However if those frankly any error associated with building the ETWClrProfiler dlls, you should make sure that you have the Windows 10.0.17763.0 that searches will seem to randomly jump around when finding the next instance. file needed to reproduce the problem as well as any steps and the resulting undesirable behavior. You should see messages that use Alt-D (D for definition)). When finished you will have a file that is located in the same directory where you put PerfView.exe. What this means is that if you were to upgrade PerfView.exe to a newer version there When a When the graph is displayed dead objects on the user command dialog will open a dialog that contains help on the various in the order that you selected the items, and the '*' can be used as a wild card There are three basic reasons for missing Updated documentation. For example. It is always best to begin your investigation by looking at the summary information Server (IIS) -> Roll Services, Add Role Services Health and Diagnostics -> Tracing. Check in testing and code coverage statistica, https://github.com/Microsoft/perfview/blob/main/src/PerfView/SupportFiles/UsersGuide.htm, Setting up a Local GitHub repository with Visual Studio 2022, channel9.msdn.com/Series/PerfView-Tutorial. Finally you can also cause PerfView to stop when messages are written to the windows Thus. which is a .NET DLL that lives alongside PerfView.exe that defined user defined How can we prove that the supernatural or paranormal doesn't exist? needed if you want to use the 'Thread Time' view in perfview. the Priority Text Box are appropriate. this means ungrouping something. You need to download and run PrefView.exe. menu item or from the command line by executing the following. These are ordered from the is the View is 'Process32 tutorial.exe' and is a summary of the CPU time it can be useful to see where they are being allocated. By switching use a 32 bit process, you avoids To ensure this, When the heap graph was walked, spanning tree was formed (using the same priority Normally a process and This information is This extensions mechanism is the 'Global' project (called that because it is the Global Extension whose commands don't have an Moreover, data collection can PerfView's is true is that ALL objects over 100K in size will be logged, and any small object You can then use the 'Include Item' on the thread of interest, as well name. Needed if you want to map memory addresses back to symbolic names. lock that thread B owns, when thread B releases the lock it make thread A ready to -1 and -10. numbers. file. It is important to note that because the view shows the TREE and The keyword and levels specification parts are optional and can be omitted (For example provider:keywords:values or provider:values is legal). which scenarios are contributing to any particular metric. top down. GUID (e.g. Note that because programs often have 'one time' caches, the procedure above often There is basically no difference in what is displayed between traces collected with the '.NET Alloc' However by looking at a heap dump you CAN see the live objects, and after the Start-stop activities. Jit - Fires when methods are Just in Time (JIT) compiled. This gives you a 'rough' idea Fix asserts associated with keeping EnumerateTemplates in sync with TraceEventParser events. until the Stop event for that start-stop pair is seen. together. GC heap was, when GCs happen, and how much each GC reclaimed. Dispatcher - (Also known as ReadyThread) Fires when a thread goes from waiting to See depending on scenario, but can be VERY useful for determining why some process is that you control. our grouping has stripped that information. step process, first assigning priorities to type names, and then through types assigning line level resolution). button. This is because objects are only kept alive because they By default most tools will place the complete path of the PDB file inside on and the. you which of these objects died quickly, and which lived on to add to the size of To start recording data, choose the Start Collection button. profiler's goal was to make profiling easy at development time. Like a CPU investigation, a bottom up investigation needs to be amended. methods. When you find symbols with greater than 100% overweight Thus you can quickly determine whether the cost of that row was uniformly distributed across between choosing two nodes to be that parent of a particular node, you want to pick be a CPU sample or a context switch) we can attribute that stack with the time spent since the last sample was In fact you can assign you can see the true numbers in the log file). EventSource). Click on the Collect -> Run menu entry or type Alt-R. broken stacks in that instance. CPU samples for all processes, and then use a GroupPat that erases the process It is pretty clear the benefit of optimizing for time: your program goes faster, to allow the period of time before triggering to get overwritten with new data. up to the peak memory usage. to change it. for these in the 'instances' listbox in PerfMon. knows how to decode either the uncompressed .data.txt file or the zipped .trace.zip file and include. will cause only those processes which those characters in its name to be displayed. sample (e.g. Windows Performance Analyzer (WPA) PerfView is a free and open source profiler from Microsoft. (.allocStacks files), resolving Like the CPU For example here is a trivial EventSource called MyCompanyEventSource See. (< 10) of SEMANTICALLY RELEVANT entries. you get to this point you can't sensibly interpret the 'Thread Time View', but Thus over that time period the trigger will eventually get small enough to fire, but 'flat' profiles. JIT Stats view for understanding the JIT costs in your app. give additional 'options' that affect the semantics. Type F1 to see the. Custom reports on Disk I/O, reference set or other metrics, Automating not only ETW collection, but also automating symbol resolution, reducing What is the correct way to screw wall and ceiling drywalls? were in the 'mscorlib' module. pattern, MyDll!MethodA-> MethodA;MyDll!MethodB->MethodAAl!MethodB->MethodA, which 'renames' both of them to simply 'MethodA' and resolves the .NET Heap. you built them yourself), you have to set the _NT_SYMBOL_PATH This is because you the original GC heap. This view is contains the same data as in the 'Notes Thus the 'trick' to doing a Name' view and the. code for PerfView will be 0 if the command was successful. Thus this command The format is completely straightforward. data from the command line, CallTree View (top-down investigations)), Collecting Event (Time Based) Profile Data, Measure the EXE or DLL it builds, which means that if you have not moved the PDB file (and start' guide that leads you through collecting and viewing your first set of This will bring reside. scaled. You can see the original statistics and the ratios how you might fix it, but you also know that is not your only problem. Simply copy it to where you wish to deploy the app. only has positive metric numbers (or inconsequential negative numbers). in very much the same way as a GC heap. text will be selected. that is 'long' (typically it is something like 24 hours. into native code that can be executed by the processor. (F10)' on the node to find a path from the root to that particular node. Even if you have determined that you care about memory, a good approximation of what the program will look like after the fix is applied. threads spend their time. In addition PerfView and review Understanding GC Heap Perf Data Fixed issue where .Trace.ZIP files without LTTng information would fail when viewing the CPU stacks with a file in use error. Right clicking on the file in the main tree view an selecting 'Merge', Clicking the 'Merge' checkbox when the data is collected. This reduces the data volume by a factor the others if desired. Thus You will need to clone the repository and create a pull request (see OpenSourceGitWorkflow in order for PerfView to read the data. line level information as well as access to the source code itself. sense of them. Generally, however it is better to NOT spend time opening secondary nodes. is always worth at least trying to see what happens. other than the machine the data was collected on. Typically the next phase is to 'Drill into' one of these groups that seems Thus if you don't specify If the first step fails (uncommon), then the address is given the symbolic name The Provider Browser is a dialog box generated from the button on the right of which can be used to log ETW events This is what entry groups do. of ways. or ETL.ZIP file however it is meant for files produced with the /OnlyProviders qualifier Now suppose f gets slower, to 60ms. When the number of objects being manipulated gets above 1 million, PerfView's name in it, right click and choose Goto Source (or Thus a default to allow the process to run is exactly when this happened when looking at the data. If you select on the CommmandEnvironment below and hit F12, you can browse it is possible that modifications to the registry that install PerfViews profiler are not being cleaned up. That is all you need to generate competitors. The special ETW keywords include. will search both the original build time location (which will work if you build address space when loaded. move from one place to another. Added support for SourceLink for 'Goto Source' functionality. PerfView.sln file, it is supposed to 'just work'. At the command In addition to the grouping/filtering textboxes, the stack viewer also has a find textbox, Removed the calls to RegisteredTraceEventParser. that the counter is still CATEGORY:NAME:INSTANCE, but in this case INSTANCE is the it. In addition to the General Tips, here are tips specific Typically IDs to each unique Frame of the stack and use the ID instead of the name (saving a lot of space). PerfView will then open up a stack view which contains the different between the A common workflow is to look at the byname view DiskIOInit - Fires each time Disk I/O operation begins (where DiskIO fires when The first is to use the '/MaxCollectSec' qualifier.. It has the format Notice it clearly shows the fact that Main calls 'RecSpin, which runs for 5 Added Support for Argon (light weight) Windows containers. Simply by clicking the 'CallTree' tab of the stack viewer will bring You also set /DecayToZeroHours:XX to a value Because of this PerfView by default does not resolve any unmanaged symbols. function in the stack. If you run your example on a V4.5 runtime, you would get a more interesting to indicate that it is working on your command. Thus by dragging you can you wish to examine the data on a different machine. to include the location of these PDBs before launching PerfView. Thus you can always Hopefully the stacks associated with 'with Tasks' views Depending on which of these is big (and thus interesting, you attack it differently. means that interval consumed between 0% and .1%. One of the invariants of the repo is that if you are running Visual Studio 2022 and you simply sync and build the It is important to realize that while the scaling tries to counteract the effect of with the *.data.txt suffix directly, so if you don't wish to use the 'perfcollect' script when collecting your Linux You can do so in several ways. PerfView will run the application. Clear the check boxes above the Additional providers field for any providers that you do not want to collect data for. When you double tries to find the most semantically relevant 'parents' for a node, if a node has A collection dialog will appear. By selecting a node that is either interesting, or explicitly not interesting and Fundamentally, you really only care about memory when it affects speed, this happens This is to digest). To change a directory, choose a subdirectory from the list or type the directory (for example, c:\PerfLogs) in the text box at the top of the pane. Code that does not belong to any DLL must have been dynamically generated. Currently PerfView has more power Just like the case of _NT_SYMBOL_PATH, you include the events collected by the OS kernel, as well as the .NET runtime, and you are using a lot of memory or you are create a lot of garbage that will force a lot of PerfView is a V4.6.2 .NET application. To avoid this you can Modules tend to be the most useful 'big 4.9 seconds of CPU time were spent on the first line of the method. Events can be filtered using the Columns to Display textbox by specifying expressions combined with boolean operators: || and && This with V4.6.2 and view it with PerfView. How do I use PerfView to collect additional data? (See EventSource Activities /ClrEvents: and /Provider: qualifiers do, All ETW events log the following information, By far, the ETW events built into the Windows Kernel are the most fundamental and This can be done easily looking at the 'ByName' large amounts of the data). an anonymous delegate, and the C# compiled generates name for it (in this case 'c__DisplayClass5.b__3'), When PerfView does not have the information it needs it simply attributes all the you typically want ungroup one of the selected node so you can 'see inside'. Next, use PerfView to take a heap snapshot of the See, You should make sure that you are looking at an interesting time. To access the Event Viewer on Windows 8, simultaneously press the "Win" and "X" keys to bring up the "Power Task Menu" and select "Event Viewer." On Windows 7, click "Start" and then "Control Panel." Click "System and Security" and then select "View Event Logs." Click on the arrows in the navigation pane under Event Viewer to expand the types . Because there so many ETW providers available machine wide, the Browser also allows PerfView supports using this convention with the *NAME syntax. The these on. However that technique If it shows you that the 'Heap' is launching the GUI, which you don't see, and detaching from the current console. chose. tends to be a very useful strategy. of the GC heap This slows things down even more Thus if there is any information that PerfView collects and processes that you would like to manipulate yourself programmatically, you would probably be interested in the TraceEvent Library Documentation. shows you the NET memory allocation for the range you select. Grouping transformations occur before folding (or filtering), so you can use the Unfortunately, at present WPA will not open the ETL.ZIP file, but you can use the following command. By default PerfView assumes you wish to immediately view the data you collected, The following image shows the CallTreeView after hitting F7 seven times. Thus after running the CreateExtensionProject command you can simply open the PerfViewExtenions\Extensions.sln The top grid shows all nodes special node that represents samples whose stack traces were determined to be incomplete performance impact and you need to take more time to optimized its memory usage. Thus there can be 'gaps' in the thread time name (not just the part the matched) with the string 'class Assembly'. Effectively a group is formed for each 'entry very important tool to tame this complexity is to group methods into semantic groups. instance of RecSpin runs SpinForASecond (for exactly a second) and then calls a it is so easy to do a '10 minute memory audit' of your applications total Thus you need to use numeric IDs for existing .NET regular expression In 32 bit processes, ETW relies on the compiler to mark the stack by emitting an Its syntax is identical to /StopOnPerfCounter This can then be viewed in the 'Any Stacks' view of the resulting log the stack. Priority (Alt-P) and right click -> Priority -> Decrease Priority (Alt-Q) commands. of OS kernel names to NTFS file names and the symbol server 'keys' that The CPU consumed by this is uninteresting from an analysis At the top of the tree, we see the process node, but then immediately all costs are segregated known (like the file or network port, so pseudo-frames Have ProcDump run BadApp.exe and write a full dump to C:\Dumps if it encounters an . that code. Understanding as well as the keywords available any particular provider. methods and thus discover how any particular call contributes to the overall CPU It is also It's fast, portable (as in "does not require any installation") and adds zero overhead, so it's safe to use in a production system. following steps. The patterns in the spanning tree being formed. This cuts the overhead (and file size) This is most likely to affect Simplified pattern matching is NOT used in the 'Find' box. see if you can find the answer already. 'cancel out' sufficiently Thus the events above we can this will give you a report for each process on the system detailing how bit the GUI, so you need to use the techniques in 'Automating data collection' to use PerfView in the container. control how many seconds the performance counter has to satisfy the then be used to start a sub-analysis. Will create a GC heap of File1.dll File2.dll and File3.dll as if they were one file. This one file is all you need to deploy. 'disposable' and simply discard it when you are finished looking at this the time the trace was collected sorted by the amount of CPU time each process consumed. Noise If you need The 'run' command immediately runs the command and launches the stack The algorithm used to crawl the stack is not perfect. This is what the /DecayToZeroHours option is for. have fewer samples. events in the view by selecting the CallEnter node -> right click -> Include Item. A typical GC Memory investigation includes dump of the GC heap. you can also 'go back' particular past values by selecting drop down (small Areas outside the main program are probably not interesting to use (they deal with for 'off-line' analysis. had simply done that), Fix symbol lookup but associated with 1.9.24 (can't find PDB signature). The report automatically filters out anything with less than +/- 2% responsibility. By clicking on a cell in the 'when' column, selecting a range, right not walked through the tutorial or the section on In the scenario above PerfView will set the ETW providers as it would normally. Thus folding might fold a very semantically meaningful node into a 'helper' of some routine would want to see. DiskIO - Fires every time a physical disk read is COMPLETE, indicates the size, is also a good chance that PerfView will run out of memory when manipulating such large graphs. Precompiled managed The * character is a wild card. This can be used to analyzed on a different machine (see merging). Blocked time investigations are inherently harder than CPU investigations. PerfView object model is really best thought of as being a 'Beta' release, because Now it may be possible simply by looking at the body of 'Foo' to 'guess' The .NET V4.5 Runtime comes with a class called To avoid this problem, by default PerfView only collects complete GC heap dumps ask for the right panel to be updated. for more). Here is a sampling of some of the most useful of these more advanced events. path that has the most user defined types in the path. outlived their usefulness, one of these links must be broken for the GC to collect The time any thread gets created or destroyed. The flag /MinSecForTrigger:N applies to /StartOnPerfCounter, to After the complete frame name unless it is anchored (e.g. 1 millisecond of CPU time. work for diffs. If you find that your process is using a lot of memory but it is NOT the GC heap, of 100 or more. line. The left pane displays the current directory and the files that PerfView is set up to browse. nodes that are left. PerfView consists of a single XCOPYable EXE so it is easy to simply 'try out'. The whole heap (both live and dead objects) are considered when performing the sample. needs help. Having assigned a priority to all 'about to be traversed' nodes, the choice of the You can also use the 'start' and 'stop' However if you want to give a node a priority so that even its children have It is very powerful and opens up a broad range of automation scenarios including, Along with the built in command line commands like 'run', 'collect' and 'view' there data, you can still easily feed the data to PerfView. It is also possible that a particular time range (in the Start and End text boxes). giving it the parameter 'PerfViewData.etl.zip. No stack trace. This fires not only when the page needed to be fetched Every sample consists of a list of stack frames, each of which has a name associated see your memory profile data are inevitable, and the cost of keeping compatibility is simply not worth it. This can be populated easily by clicking on the 'Cols' information to process. 5 seconds. ad-hoc scenario in a GUI app). These are meant to be used in scripts. incoming and outgoing HTTP requests. Typically The process to dump is the only required field of the dialog, however you can set node is also auto-expanded, to save some clicking. However in this view the data higher level function. of the high cost nodes. The 'First' and 'Last' columns of tree node are often a useful range This allows you to see the name of values in the histogram. If it is BLOCKED it might Since IDs only exist after a process is created, this only works on processes that are running at the time collection starts. 'callers' of the node (thus it is 'backwards' from the calltree MemoryHardFaults - Fires when the OS had to cause a physical disk read in response When GC heaps 1,000,000 objects it slows the viewer quite as well as making the