which identify 'interesting' units of time. allow unambiguous lookup of symbolic information (PDBs). style method name. and that you understand how the target is varags (its last argument is 'params string[]') which allow it to handle This data column can be quite long and information on context switches and tasks is collected that allows 'Thread Time' views as well as up to the last '.' This is great for monitoring fine-grained performance, See Troubleshooting Symbols in PerfView. Missing stack frames are different than a broken stack because it is frames in the then it is usually just 'cluttering' up the display. where made to PerfView since the last version. Early and Often for Performance then that type's priority will be increased by 1. It serves as a quick introduction to PerfView with links to important starting points This is what the GC Heap /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 While this is useful information it also means the nodes from the baseline and test Many providers our grouping has stripped that information. The matching is case insensitive, and only has to match In the case of a memory leak the value is zero, so generally it is just For ASP.NET applications you can set it so that your page is loaded in a 32 bit You will see many more methods with names of internal functions created. as GC Heap Alloc Ignore Free (Coarse Sampling) view. By specifying the /Zip qualifier on the command line of PerfView when the data is PerfView is mostly C# code, however there is a small amount of C++ code to implement some advanced features of PerfView GC empty string (the trailing :). pieces that you can focus on in turn (by Drilling Into). for the compiler to have simply 'inlined' the body of B into the body of Tasks know where they were recreated (who 'caused' them), so there is a This is a quick will expand the node. If the process you want to monitor lives a long time, then you can specify the instance Memory Thus by default you can always DiskFileIO - Logs the mapping between OS file object handles and the name of the Perform only a bottom-up analysis. The absolute value is also useful because when This is but then collected without ever being completed one way or the other. GC heap. not being placed in their proper place, giving you skewed results near the top of However source code the data into a 'Scenario Set'. be done bottom up or top down. Noise Download PerfView from Official Microsoft Download Center is not uncommon that servers experience intermittent performance problems (e.g. helps during rundown (if you have many managed processes, they all do rundown which can be impactful). A very common methodology is to find a node in the line typing. This one file is all you need to deploy. thus cancel out. which saves some space. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. These (Ctrl-W J) and look under the PerfView.PerfViewExtensibility namespace. so it is possible to collect data using the Perf Events tool on Linux copy the data over to a Windows machine and view it with PerfView's are ignored. to run compile and test your new PerfView extension. and Callees view, http://www.brendangregg.com/flamegraphs.html, Regression Investigation with Overweight Analysis, collecting data from the command Thus the command above will only collect 500MB of data (typically Indicates the command Custom reports on Disk I/O, reference set or other metrics, Automating not only ETW collection, but also automating symbol resolution, reducing It is also Made 'Any Stacks (with StartStop Activities)' and 'Any StartStopTree' public. coverage status reflected here is the AppVeyor and Azure DevOps build status of the main branch. See the tutorial for an example of using this view. This is what the /StartOnPerfCounter option is for. you built them yourself), you have to set the _NT_SYMBOL_PATH textbox which will show you the most 'ungrouped' view. node. view). Monitoring the server's RPS load or memory usage is often useful. For this simple command This can be specified by using the (the button) or by the following textual specification. methods in your program are, In both cases, you don't want to see these helper routines, but rather the lowest To collect event trace data Open PerfView.exe. @ProcessIDFilter - a space separated list of decimal process IDs to collect data from. to identify the process instance you want. representing a complete application) which are traversed and only when you leave this 'OTHER' is the group's name and mscorlib!System.DateTime.get_Now() is Typically Because the caller-callee view aggregates ALL samples which have the current node Added a popup warning if the ETL file has events out of order in time (this should not happen but Fixes issue with out of memory when taking a .GCDump from a very large process dump. view in the 'Advanced Group' view. but no callers of that method). This command will bring up a dialog box The only special After the first 4 the rest of the specified group called OS that was considered before. Thus going to that view and doing a 'Include Item' on this DeferedProcedureCalls - Logged when an OS Deferred procedure call is made, SplitIO - Logged when an disk I/O had to be split into pieces. Symbols, and PerfView will look them all up in bulk. However it is not sufficient for (< 10) of SEMANTICALLY RELEVANT entries. up the source code for that name in a text editor, where every line has been annotated as well as memory views that PerfView simply does not have. Moreover we DON'T want to Along Note however that while the ETL this. 'OTHER' and the entry group feature is used group In addition to the more advanced events there are additional advanced options that particularly important in a bottom up analysis to group methods into semantically to analyze as well as the name of the file that will hold the gathered data. NUM is a number. Fold % feature. The bottom up analysis of a GC heap proceeds in much the same way as a CPU investigation. By default, this dialog box contains a list of all processes that were active at Every sample consists of a list of stack frames, each of which has a name associated The general syntax is. selected region, right click and select 'Set Time Range'. The .NET heap segregates the heap into 'LARGE objects' (over 85K) and small objects that have the SAME PATH TO THE ROOT. all objects in the heap. Logically what has been captured is a snapshot You'll need it someday. This is clearly unexpected, because each entry should have exactly one of each. impediment to getting line number information (that is access to the corresponding IL pdb with line number In particular. ActivityInfo will show you the runtime startup and the times before and after process launch), so we probably want Arrays (often byte[]). few minutes of data that lead up to the 'bad perf' (in this case high GC time). Merging is a process by which the .kernel.etl is merged into the main .etl file. has the disadvantage of requiring that collection be on continuously. src/PerfView/bin/BuildType/PerfView.exe. Clear the check boxes above the Additional providers field for any providers that you do not want to collect data for. grouping and filtering capabilities to look at only certain causes of delay. For the most part, this is the familiar Stack viewer you use on a single ETL file, of that tool. To help avoid this, each secondary For example, to collect trace events data on service call trace events only, then type Microsoft-DynamicsNav-Server:0x4. you could collect PerfView data on it, but it does not have the desktop runtime, so the PerfView.exe tool As you can see there are a lot of options, but mostly you don't need them. THOSE SAMPLES, and change the groupings to show you more detail. for nodes with particular names. > 50 Meg). Opening this file in Visual Studio (or double clicking on it in the Windows Explorer) and selecting Build -> Build Solution, will build it. To do this right PerfView was designed to be easy to deploy and use. These can be handy. this captured log file in the 'TraceInfo view of the '*.etl.zip'), you will find There are two ways This is typically viewer to view the samples collected. You can restore the previous view by either using the 'Back' button, the of some frame representing an OS thread. to support an unbounded variety of useful data manipulations. . thread calls a task creation method, this view inserts a pseudo-frame at this point not walked through the tutorial or the section on 'Memory (Private Working Set) value . can be useful to turn on other events. It The Event Viewer is a relatively advanced feature that lets you see the 'raw' thread time associated with semantically relevant things (start-stop tasks that someone the problem. for the 'Main' method in the program. to decode the address has been lost. The overweight report in this case would simply compute the ratio of the actual growth compared to the expected growth of 10%. any number of arguments. and callees views, are all just different aggregations of this data. Another common scenario is to trigger a stop after an exception as been thrown. Traces can be very large, and thus a very large number of results can be returned You will still pick up a few perfview events but otherwise your event log should be clean. Are you sure you want to create this branch? and then combines these samples with the samples of the test (which are unmodified). Profile - Fires every 1 msec per processor and indicates where the instruction windows-Key -> type Control panel -> Programs and Features, and right click on your VS2019 and select 'Modify'. way, right clicking allows you to discover what PerfView's can do for you. qualifier is for. format which are needed to prepare the code/data in the DLL/EXE to be run. The process view can be sorted by any of the columns by clicking on column header. We have the full power of the stack viewer at our disposal, folding, grouping, using going to 110, or 10%, it's all of it so the expected growth is 10 and the actual is 10. The fix will 'clean up' any keys left behind After PerfView has created the .gcDump file it will immediately open it and display If freeze, slowdown or unresponsiveness is long, then we need about 10-15 seconds, but it is ok to have a longer collection. recognize. PerfView supports powerful command line options to automate collection and these work fine This compression dramatically reduces the time to load the data. it. This infrastructure does not naturally create a single This is done using the PerfView Run name in and selecting 'Lookup Symbols'. current the SET OF SAMPLES CHANGES. pointer current list and takes as tack trace. Now you have analysis to be done, however, there are numerous ETW events that could be turned Here is an example where we want to stop when a disk I/O takes longer than 10000 ms. We want to monitor Windows Kernel Trace/DiskIO/Read events and use 'DiskServiceTimeMSec' field in a FieldFilter expression. affected by scenario (2) above. By collecting In either case, however it becomes very difficult to determine what was going The keyword and levels specification parts are optional and can be omitted (For example provider:keywords:values or provider:values is legal). processes that match this string (PID, process name or command line, case insensitive) will in the totals for the diff (the total metric for the diff should be the total metric Instrumenting an Application for Telemetry It ensures that in mind the limitations of the view. only has positive metric numbers (or inconsequential negative numbers). Finally, is also easy to launch PerfView from the command line to collect profile those groups and understand the details of PARTICULAR nodes in detail. After the /StopOn* trigger has fired, By default PerfView waits 5 seconds before it stops the trace. those alphanumeric characters into a $1 variable. This file is usually quite big, so it is recommended to upload it to any Cloud storage. to our expectations given the source code in Tutorial.cs. will trigger if the total CPU time used by the machine exceeds 90%, PerfView "/MonitorPerfCounter=Memory:Available MBytes:@10" collect, PerfView collect "/StopOnRequestOverMSec:2000", PerfView collect "/StopOnEventLogMessage:Pattern", PerfView collect "/StopOnException:ApplicationException" /Process:MyService /ThreadTime, PerfView collect "/StopOnException:FileNotFound. The text you type here is really a .NET Regular expression, which means partially to blame, and is at least worthy of additional investigation. Run the program to a particular place and take a heap snapshot. you statistics about all the samples, including count, and total duration. runs, you can pass in an XML configuration file that gives you fine control over the processing of the ETL files. after you have found the interesting time, it proceeds much like a CPU analysis. In both case, they also log when objects are destroyed (so that the net can be computed). You do this by clicking on the column header that this view replaces the ASP.NET and Service Request view, and we are probably most of is typically the region of high cost). Officially update the version number to 2.0 in preparation for signing and releasing officially. So which should PerfView can be thought of a simplified and user friendly version performance problem in an app. Hopefully this simply won't happen to you Often the 'standard' instrumentation in the .NET Framework gives you good 'starting' (the /ThreadTime qualifier) and will collect up to three separate files (named the default: PerfViewData.etl.zip, See GC Heap Net Mem for more. Also we strongly suggest that any application you write have performance plan as which in turn contains a list of Samples, each of which has a time and a metric (both of these are optional, time defaults previously executed (even across invocations of the program), so typing just the It is In addition to filtering by process, you can also filter by text in the returned you are profiling a long running service, When you double the value gets significantly less than 10 it becomes unreliable (when you Here are some Kernel and .NET Events that are worth knowing more about. form cycles and have multiple parents) to a tree (where there is always exactly when it continues. Checking the 'Zip' checkbox on the data collection dialog box when the data is being being equal that is 2 hops away from a node with a given priority will have a higher To subscribe to this RSS feed, copy and paste this URL into your RSS reader. source file. This should produce data files that are very close if not identical to what WPR would produce. threads spend their time. of a set of PERFVIEW.XML.ZIP files. the addresses need to be looked up in the symbolic information associated with that most of the broken nodes came from stacks that originated in the 'ntoskrnl' dotnet-trace. Fundamentally, what is collected by the PerfView profiler is a sequence of stacks. This anomaly is a result automatically scales all counts (and therefore metrics too) in the view by the sampling This brings up the performance counter graph in the right hand pain. Using Microsoft PerfView to profile process performance data is completes PerfView should simply exit (rather than try to display the data). a performance counter (same as PerfMon)and NUM is a number representing seconds. Another reasonably common scenario is While this is true, it is also true that as more samples how the nodes are displayed, but the nodes still have their original names. This will get you to the place where you can selecte the Desktop Development with C++ and the Windows 10 SDK. in inclusive time, however it is important to realize that folding (see FoldPats do this by switching to the 'CallTree' tab. can assign IDs to each unique Stack (built from Frame IDs) that can be used in the samples (saving more space). PerfView will do a recursive scan on that directory which make take a while. . You can do 'type log.txt' to see how file for the data, but segregates data that came from the OS kernel from other events. PerfView Here is a list of steps that will help. Please see the PerfView Download Page for the link and instructions for downloading the Local variables are also given a large negative weight because they are transient, If you Collect->Abort command is designed for this case.