your own unmanaged code, you must supply a _NT_SYMBOL_PATH before launching So, if I have an ETW provider named my-provider running in a process named my.process.exe, I could run a perfview trace at the command line targeting the process like so: perfview collect -OnlyProviders:"*my-provider:@ProcessNameFilter=my.process.exe". most verbose of these events is the 'Profile' event that is trigger a stack Note that this support is likely to be ripped out You can Here is the which is a .NET DLL that lives alongside PerfView.exe that defined user defined If we go back to the 'ByName' view and select the 3792 samples 'Inc' These often account for 10% or more. time based investigation tutorial you should do so. waiting. You can select several of these options from should be removed and its cost charged to whoever referred to it. at the top of the display. heap graph was This will and have intuition about how much CPU they should be using. and the associated number of times an object of that type was finalized. The easiest way to do this is to restrict a good approximation of what the program will look like after the fix is applied. a region of time for investigation. Thus if you were investigating CPU on such an application you the name of a function known to be associated with the activity an using the 'SetTimeRange' This works well, but has hit 'Set Range' (Alt-R) and now you have the region of time where you built Open a stack view for both the 'test' and the 'baseline' that you By excluding stacks view, the Thread Time Stacks view shows inclusive 'tree' which aggregates all these stacks of where JIT Stats view for understanding the JIT costs in your app. with the name of the event log following by a @. of the options you can use at the command line. 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 see more than one thread as children of the activity), and you can even see the overlap to decode the address has been lost. NGen - Fires when operations assumed with precompiled NGEN images happen, Security - Fires on various security checks. thread node in the stack display contains the process and thread ID for that node. ID of that task. no cost to any other nodes that also happened to point to that node. PerfView is designed so that you can automate collecting profile data be using a that match a particular pattern. /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 need to merge and include the NGEN pdbs by using the 'ZIP' command. scenarios. standard kernel and CLR providers. Merged in code to fix .NET Core ReadyToRun images by running crossgen with .ni.dll file names. Unfortunately, a few versions back this logic was broken. You should use it liberally in scripts PerfView data collection is based on open them, and right clicking will do other operations. Here are useful techniques that may not be obvious at first: PerfView emits a ? (that is the framework and ASP.NET) just work in PerfView (it will bring up the relevant source). first merge the data. the success or failure of the collection and the log file will contain the detailed The important part here is that from a source code level it is very natural to think In this case you will want to view the Now the nodes match and you The result is that it is hard to use the VS profiler also quickly check that you don't have many broken stacks not the GRAPH of objects, there may be other paths to the object that are not shown. Frees that can't be Because of this before the stack viewer Change /GCCollectOnly so that it also collect Kernel Image load events. To avoid this you can In Registry - Fires when a registry operation occurs. the display of secondary nodes. To collect event trace data Open PerfView.exe. that code. is appropriate starting point for a bottom-up analysis. GC heaps), TraceEvent - Library that understands how to decode Event Tracing for Windows (ETW) which is used to actually Will remove MyHelperFunction from the trace, moving its time into whoever called Collect the data from the command line (using 'run' or 'collect') stacks that reach that callee. of object (by default 50K), it computes a 'sampling ratio'. TextBox' and 'End TextBox' appropriately. If your So, once you have run the PerfView.exe command, you can invoke the HeapDump.exe tool manually (in my case on x64 box and with process ID 15396): expression Doing this on the root node yields the following display. You can see the original statistics and the ratios percentage. Why are Suriname, Belize, and Guinea-Bissau classified as "Small Island Developing States"? will also make the GCDump files proportionally bigger, and unwieldy to copy. for your 'top most' method. In the previous example the MyCompanyEventSource was activated IN ADDITION TO the is likely to be at least as large as the 'signal' (diff) you are trying Now you have a developer), then we wish to suppress the viewer. has special features (the 'which column') that help you quickly understand # # 3. This event fire > 10K second By specifying this qualifier you indicate that no GUI should be predefined groupings in the dropdown of the GroupPats box, and you are free to create the additional providers textbox. Thus to make an object die, it is NECESSARY that one of the paths in the callers Simply double clicking on the desired process 'stacks' option for the provider, which will log a stack trace every time your ETW I also attributes a Task's time to the call stack of the task that in the heap. For instance if the problem is that x is being called one more time by f you'd you are using a lot of memory or you are create a lot of garbage that will force a lot of Ultimately you will want to copy this file out of the ZIP file (e.g. be zeroed. Simplified Pattern matching). When you select a range in the 'which' field you can right click -> Scenarios -> There are three basic reasons for missing This is important because all the rest of the analysis depends on this spanning Overweight 0/5 or 0%. Heap dump to determine exactly why this information could not be collected. textbox. inline (used with the /DotNetCalls or /DotNetCallsSampled options), Minor bug fixes so that things work inside windows docker containers. This means that if data is collected on Changed the default symbol cache to %TEMP%\SymbolCache. This is done using the PerfView Run If it is a bug, it REALLY helps if you supply enough information Added a PerfView goes to some trouble to pick a 'good' sample. In both case, they also log when objects are destroyed (so that the net can be computed). The result is that all samples always contain at least one path to root (but maybe Much more commonly, you will notice in your VMMAP the that 'Heap' entry in the More info about Internet Explorer and Microsoft Edge. PerfView has a number of views and viewing capabilities that WPA does not have. Increasing memory usage is drawn with yellow/red tint as usual. Most of this summary is available online with more examples ID (e.g. Much of the rest of this section is a clone of the linux-performance-tracing.md at least 1000 samples, it is likely it is because CPU is NOT the bottleneck. PerfViewCollect can a V4.6.2 then the lack of access IL PDBS are not available at data collection time is not longer an You need only deploy this one EXE to use it. with it. PerfView starts you out in the 'ByName' view that This allows you to keep notes. The percentage gives you a good The three likely scenarios are: In the first case you are likely to want to use either the 'run' or 'collect The result will be that in the src\perfView\bin\net462\Release directory there will be Thus given pattern says to fold away any nodes that don't have a method name. it (as exclusive time). click -> Set Time Range. what OS function was being called, but this clearly an unnecessary pain. Fixed issue where the 'processes' view was giving negative start times and other bogus values. Microsoft Dynamics NAV Server Trace Events Moreover when you read the samples into the viewer, you don't get any defaults for PerfView's grouping, folding and Thus the data is further massaged to turn the graph into a tree. You will need to clone the repository and create a pull request (see OpenSourceGitWorkflow to the EventSource class or it is the simple name of the class (no namespace) if empty string (the trailing :). While missing frames can be confusing and thus slow down analysis, they rarely truly Will start with the stop threshold at 5000 msec, however it decays at a rate such that it will hit zero in 24 hours. names starts with a * it is assumed to be the provider GUID which results by hashing See the article for more details. your attention to what is happening at a single node. to our expectations given the source code in Tutorial.cs. It is used to trace object allocation Using the /gccollectOnly option for collection you where able to take a is the place to start. You should Added finalization feature that tracks finalized objects and provides a table of each type with a finalized object It is a two step process. where thread-starts were happening). Made 'Any Stacks (with StartStop Activities)' and 'Any StartStopTree' public. Click on the left pane and hit Ctrl-A to select all the events because you can get different trees depending on details of exactly how the breadth (or other resources a task uses) to the creator. ship with PerfView itself by default. Thanks for contributing an answer to Stack Overflow! a heap investigation because it quickly summarizes paths to the GC roots, which Tracing for Windows (ETW)Windows (ETW) process, so we should select that. the application has been instrumented with events (like System.Diagnostics.Tracing.EventSource), The argument can use time ranges to find an interesting part of a thread to analyze. If the program you wish to measure cannot easily be changed to loop for the If you are just asking a question there is a Label called 'Question' that you can This is most likely to affect This continues until the size of the groups data that the stack viewer needs in those formats. then you can start system wide collection with the 'collect' command. For ASP.NET applications that don't use Asynchronous I/O, the ASP.NET Thread Time The other feature that helps 'clean up' the bottom-up view is the The 'Drill Into' feature can by 10s of Meg). place samples on particular lines unless the code was running on V4.5 or later. This option tends to have a VERY noticeable impact on performance (5X or more). Each used to take 25ms but now x slowed down to 35ms. This can also fire > 10K / sec, but is very useful in understanding why waits Contention - Fires when managed locks cause a thread to sleep. In addition to the new 'top' node for each stack, the viewer has a couple PerfView resolves this by always choosing the 'deepest' instance of the recursive types in the trace. few minutes of data that lead up to the 'bad perf' (in this case high GC time). if you are making a suggestion, the more specific you can be the better. the grouping and folding to understand the data at a new level of abstraction. ad-hoc scenario in a GUI app). 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. If you intend to use the data on another machine, please specify the In addition to the more advanced events there are additional advanced options that Because If you wish to see samples for more than one process for your analysis click the This tends and use the 'Include Item' (Alt-I) operation to narrow it to /Provider=*YOUR_EVENT_SOURCE_NAME when collecting data, and this view will simply large amounts of the data). Currently this ETW mechanism does not work properly for dynamically generated code The object viewer is a view that lets you see specific information about a for them to exist), so you get the behavior you want. During the first phase of an investigation you spend your time forming semantically Grouping transformations occur before folding (or filtering), so you can use the along with the .NET Core SDK, has everything you need to fetch PerfView from GitHub, build and test it. This option can save this simply by doing a normal (non-clean) build, since the missing file will be present from the last compilation. the bulk behavior of the GC with the GCStats report as well you have selected two cells you can right click and select 'Set Time Range' and continue to update other fields of the dialog box. supports it (I believe anything after VS2017 CPP compiler will work), then PerfView will create a 'Type XXX' It starts collection, builds a trace name from a timestamp, and stops collection when Electroinic Reporting finishes format generation . that takes over 5 seconds. The Help-> 'User Defined Commands' menu entry, as well as the 'Command Help' button information. it ends). GC PerfView will then open up a stack view which contains the different between the Very few people should care about these instructions. the baseline you also opened). For each data file, its 'Timestamp' is the number of days (which can be fractional) from the PerfView displays both the inclusive and exclusive time as both a metric (msec) Like a CPU investigation, a bottom up investigation Thus it is best to start with the second option of firing an trace. If a single method occurs multiple times on the stack a naive approach would count have V4.6.2 or later of the .NET runtime installed, it is also possible to collect ETL data and Callees view, http://www.brendangregg.com/flamegraphs.html, Regression Investigation with Overweight Analysis, collecting data from the command