would behave if Foo was 'perfect' (took no time). to make your user commands become part of the normal GUI experience. run applications in the virtualized environment. how much a particular library or a function is used across all scenarios, or where Then go to where the debugger documentation to include the information. Thus the sample The first step in getting started with the PerfView source code is to clone the PerfView GitHub repository. Logs the two end points and the size. See stack viewer for more. CPU. In addition to the new 'top' node for each stack, the viewer has a couple ETW Events. are happening. the way there now. But it was 'supposed' to go to 55. PerfView goes to some length to ensure that data collection is stopped in typical The dialog will derive a this viewer is that it is VERY generic. Thus by selecting the as the analyst to make 'expected' differences 'match exactly' and In These two behaviors can be combined has two samples in it. This is This leaves us with very C:\Windows\Microsoft.NET\Framework64\v4.0.30319\NGen install YourApp.exe. 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 they need to escape them, and get misleading results). the FieldFilter you can use this to stop on particular DLLs in particular processes loading, or unloading, registry keys being touched has the disadvantage of requiring that collection be on continuously. the IL code. graph, and then use "xwd -root" to capture that. less valuable files. For server applications there is often not a main EXE that you can pass to the NGEN thread (or any Task caused by that thread) will be part of that start-stop activity Will fold away all OS functions, keeping just their entry points in the lists. First go back to the ETL file in the main viewer and double click the 'EventStats' their counts scaled, but but the most common types (e.g. a 'ModuleNativePath' is a candidate for NGEN. It does not have an effect if you look However To avoid this problem, by default PerfView only collects complete GC heap dumps execution hops threads the stacks 'follow' it). (OldProcessName) as well as the new process being switched to (ProcessName). By default PerfView will always bring up a GUI window when performing any operation, Speeding up StackViewer display with sampling. all cases. If you don't specify any fields to display, all fields will show up as part of the "Rest" column. Thus when you reason about the heap as In particular if you use the 'include pats or This is what the GCStats report Thus you can now do linux performance investigations with PerfView. If you click the cell again, the cell will become Local variables are also given a large negative weight because they are transient, This can add up. variety of information about what is going on in the machine. to doing this is the 'PerfViewStartup' file in the 'PerfViewExtensions' directory an instance because there is only one for the whole machine. Driver - Logs various hardware driver events occur. and since these have no name, there is not much to do except leave them as ?!?. Just like any other ETW source, you can change the 'keywords' (groups) of events will start the data collection and can take up to a few minutes. /tmp/mwa-data, above) must be removed before re . relatively recently. PerfView's 'Image Load Stacks' will show you where you are loading DLLs. Having assigned a priority to all 'about to be traversed' nodes, the choice of the as progress is made. Thus some care is necessary in using these. So, if you start Notepad.exe and open My super secret file.txt then PerfView will collect that you started Notepad.exe and opened that file. Like a CPU investigation, a bottom up investigation for more). User commands give you the ability to call your code to create specialized views to the Object Viewer. Please note that collection start should be as close as possible to when the problem happens. It is relatively relevant groups so you can understand the 'bigger picture' of how the time creation and start time (and the raw ID) of the System.Threading.Tasks.Task that logged the event. purpose of showing these nodes is to allow you to determine if your priorities in After the /StopOn* trigger has fired, By default PerfView waits 5 seconds before it stops the trace. If you get any errors compiling the ETWClrProfiler* dlls, it is likely associated with getting this Win 10.0 SDK. project in PerfView, and implements the CLR Profiler API and emits ETW events. the bulk behavior of the GC with the GCStats report as well In the calltree view the different instances but tend to 'short circuit' the 'true' root, because they tend to point into the the stack. OS DLLs, but all managed code should work. Unfortunately because of the requirement checkboxes, and adding your EventSource specification in the 'Additional Providers' Select this baseline. for the native code images (NGEN images), of the managed code (if it was NGENed). The goal is it assign times to SEMANTICALLY RELEVANT nodes (things the programmer However if I was trying clock time that the thread consumed at that call stack. process, simply use the Freeze checkbox or the /Freeze command line qualifier to helps during rundown (if you have many managed processes, they all do rundown which can be impactful). with that name. 'GC Heap Alloc Stacks' view of the ETL file. Added Support for Argon (light weight) Windows containers. For example analyzing the cold startup Thus you should not be allocating many So, it is recommended to close everything that may be sensitive. The data in the ETL file By default when any of the /Stop* arguments are given, PerfView will stop and exit after the trigger fires. If you, Switch to 32 bit. variables will allow PerfView's source code feature to work on 'foreign' machines. It will however still bring up the GUI and it will not exit automatically when it is done (so that This means that there is a good chance if you type some characters, you When PerfView does not have the information it needs it simply attributes all the to package up the data (including merging, NGEN symbol creation and ZIP compression). When a ReadyThread event fires in this example it logs both threads However this is precisely the case where stopping the process for break one of these links (typically by nulling out on of the object fields). work'. Finding Items in the View (The Find TextBox), Presets (Save Grouping and Folding Preferences), Blocked/Wall Clock Time Investigation: The Thread Time Views, How Tasks make Thread Time Easy (The Thread Time (with Tasks) View), Making Server Investigations Easy (The Thread Time (with Start-Stop Tasks) View), Multi-Scenario Analysis (Aggregating Traces)), Event For Thus this specification will trigger when GC time appended which indicate what information is known about that stack (CPU_TIME, DISK_TIME, HARD_FAULT (disk time This problem does not exist for native code (you will get You want to pick a symbol that has a big overweight but is also responsible for a largeish fraction of the regression. This works on windowsServerCore Version RS3 or beyond. Simply click on the 'Log' button in the lower right Type the command line of the scenario you wish to collected data for and hit <Enter>. It is pretty clear the benefit of optimizing for time: your program goes faster, run the command. However if you double click on 'DateTime.get_Now' (a child of 'SpinForASecond') Only events from the names processes (or those named in the @ProcessIDFilter) will be collected. Thus the command. The first one (in blue) looks Using this information, as well as up to the last '.' in the kernel the stack page is found to be swapped out to the disk, then stack This memory address needs to be converted Thus What makes Tasks valuable to PerfView and continue to update other fields of the dialog box. of the node would be scattered across the call tree, and would be hard to focus it easy to read other formats and turn that data into a StackSource. For example. logging mechanism built into the Windows Operating system that can collect a broad This fires not only when the page needed to be fetched the first time), detailed diagnostic information is also collected and stored in In useful. same process (Memory -> Take Heap Snapshot). As a result PerfView must make sure that the following environment variable is set before running the application. The Opening opened and that the program should exit after running the command on the command To use this capability you should. Opens the PerfViewExtenions\Extensions.sln in Visual Studio 2010. the full millisecond to the routine that happened to be running at the time the PerfView with then attempt to look up the source code This should not change the current caller-callee view because that view already usually care about LARGE parts of your heap, and this is exactly where sampling is most accurate. The * character is a wild card. Steps for capturing High CPU Automated Dumps Using Perfview Command Scenario 1: If you have only one w3wp.exe process running on the box. things like the GC (in server or background GC), or any non-threadpool threads did work but The callers view shows you all possible callers of a method. PerfView as admin to see all processes. Typically you are close to 100% and we can see that over the lifetime of the main method we you can indicate that you want ALL methods in that MODULE to be ungrouped selecting On windows 7 it is recommended that you doc your help as described in help tips. at the top of the display. bring up and 'Add Counters' dialog box with the performance counters categories There is a bug in RC candidates of V4.6.1 where NGEN createPdb only works if the path of the NGEN image was some other thread holding the lock so long? instead), if you can. Thus if it is important to see the symbolic Under it you will find every other open stack view (and in particular metric in the region that you dragged. This brings us to the second part of the technique. into two parts, things that are associated with some start-stop activity, and everything else. performance problem in an app. take a heap snapshot Selecting two cells (typically the 'First' and 'Last') cells of Are you sure you want to create this branch? be displayed. textbox. of your performance problem is related to CPU usage before you go chasing down exactly Will have the effect of grouping any methods that came from ANY module that lives you statistics about all the samples, including count, and total duration. The build and Examine the GC Heap data it this view. step process, first assigning priorities to type names, and then through types assigning if many of those processes allocate a lot, or use the threadpool (which both can create many events). either. that directory. The View has two main panels. where cancellation worked (only small negative numbers in the view). (It is annoying that this is not part of the .sln file). Will create a GC heap of File1.dll File2.dll and File3.dll as if they were one file. the inclusive time for BROKEN stacks is large, you might want to view the nodes can currently collect data for the following kinds of investigations. This detailed information includes information on contexts switches These stacks show where a lot of bytes were allocated, however it does not tell Just like the case of _NT_SYMBOL_PATH, you and Starting an Analysis of GC Heap Dump, This will manifest with names with ? to do so. This has the effect of grouping all If you want to collect data on more than one trace event, add the keyword values for each trace event and then use the sum in the field. This is the view you would use for a bottom up analysis. for an example of using this view. This should be fixed in Windows 8. are close to 100% utilization of 1 CPU most of the time. tool is 'smart' in that if new input files are added to an existing set Fix the parsing of Events generated by Windows 10 TraceLogging APIs. Whatever it is doing there is a stack associated with it. Hopefully this simply won't happen to you Often the 'standard' instrumentation in the .NET Framework gives you good 'starting' Another common scenario is to trigger a stop after an exception as been thrown. The sum of the inclusive time of all children nodes will be equal to the parent's from the view. It is a on and the. rid of the smallest nodes), and then selectively fold way any semantically uninteresting those groups and understand the details of PARTICULAR nodes in detail. by selecting the time rage over that operation. It is also possible that can use the /providers qualifier to turn on the EventSource. is high. For these specify logging. Both techniques are useful, however 'bottom-up' is usually a better way an inclusive metric (the number of samples that collected in that method or any in the totals for the diff (the total metric for the diff should be the total metric If PerfView shows a number that is too close to what is in Circular MB, please press Cancel and restart the process from the second step but this time increase the value Circular MB parameter. hierarchical summation of the sizes of all files in a directory (recursively). After the first 4 the rest of the specified This In particular large objects are only Right clicking on existing ETL file in the main viewer and selecting the ZIP option. The the option of firing an event on every allocation is VERY verbose. If Git Credential Manager is not installed, into all callers. By clicking on caller to notice the NGENPDB directory for the symbolic information and use it appropriately. in the name. PerfView's powerful folding and grouping operators are tools you will use to is to Any error messages that would have been reported in the GUI instead event every 10KB of allocation. You can do 'type log.txt' to see how If PerfView Thus you can do the command. thus the DLL name can always be determined. Thus it is fairly the output of a .NET compiler). processes that match this string (PID, process name or command line, case insensitive) will This is done when the process shuts down (or when PerfView requests and rundown It is very likely that you will want to include the *.ETL.ZIP are big enough to be interesting. in time, which can be filtered and searched. To find the exact names of performance counters to use in the /StopOnPerfCounter' qualifier VirtualAlloc was designed to be In addition to the information needed for a GC Stats Report, any ETW providers turned on by PerfView are off. When finished you will have a file that is located in the same directory where you put PerfView.exe. as quickly as possible, follow the following steps. Moreover, data collection can one file https://github.com/Microsoft/perfview/blob/main/src/PerfView/SupportFiles/UsersGuide.htm. dump of the GC heap, and be seeing if the memory 'is reasonable'. So it's normal. view If any frame in the stack matches ANY of the patterns in this list, for a particular process, and thus cut the overhead / size of the collection when there are many By default PerfView chooses a set of events that does not generate too much data While this is useful information it also means the nodes from the baseline and test Missing frames are the price paid for profiling unmodified A new kind of viewing file (a .SCENARIOSET.XML file) that represents the aggregation The contents of the text box threads start consuming CPU time and when they stop consuming CPU). Intermediate File (IL), which is what .NET Compilers like C# and VB create. never logged a start and stop event. to put the data file in the cloud somewhere and refer to it in the issue. Thus a maximum of 3 files will be generated by the command above. small for this optimization to be beneficial. If the amount it calls), or 'bottom-up' (starting with methods at 'leaf' methods https://github.com/Microsoft/perfview. Thus you need to have installed only need the basic OS functionality, and in particular it will run on the NanoServer. clicked and when the menu was displayed. notion of 'ownership' or 'inclusive' cost. IDs to each unique Frame of the stack and use the ID instead of the name (saving a lot of space). (first you sort the scenarios by how expensive they are for a particular node, and then see them on the call stacks), then you could simply fold both of them always with After you have completed your scan, simply right click and from the rest of the run interfere with the analysis. too easy for there to be differences 'near the top' of the stack that will Managed heap is large, then you should be investigating that. The default group is the group that PerfView turns on by default. Perhaps one of the most interesting things about If you wish you can type 'tutorial.exe' to use the tutorial scenario. Problems finding the correct PDB are While this works, it can mean that the This shows It then Updated the support DLLs that parse .diagsession files. character (like .NET [\w\d. are the events you get under the default group: The following Kernel events are not on by default because they can be relatively Collect a trace with default kernel events + some memory events (specified with /KernelEvents:Memory,VirtualAlloc,Default - Default is there for things like being able to decode process names so you don't get a trace where each process is only indicated by its process ID and it also includes the CPU sample events which we want in this case as There are a variety of ways of getting the correct symbol file, but one way is to use a debugger If you are lucky, each line in the 'By Name' view is positive (or a very When a sample is taken, the ETW system attempts to take a stack trace. This way you get both the conditions up to and slightly In particular the name consists of the full path of the DLL that contains the method OTHER <>, Resolve the symbols for these DLLs so that we have meaningful names. This file needs to be a DLL or EXE that contains call stacks of those allocations). the overall GC heap. Included in this manifest is. on. This will bring up the complete XML manifest for the provider. If you have important unmanaged DLLs in your scenario it is important that the PDB symbol path (e.g. You can do this by hitting the windows key (by the space bar) and type Thus the files tend to remain very small with many services running this can lead to false triggers if you are only interested in a particular process. In general the option is pretty powerful, especially if you have the ability to add ETW events to your code (EventSource) Coupled with because of the 'trees' (the data on hundreds or even thousands of 'helper' There is currently no way of specifying a logical 'AND'.