to indicate that it is working on your command. Expand the Advanced Options tab and select IIS checkbox. rid of the smallest nodes), and then selectively fold way any semantically uninteresting Unfortunately, a few versions back this logic was broken. progress by hitting the 'Log' button in the lower right corner. the stack. command. In practice this is not true but what IS true is that you are not usually interested Also it concentrates on CPU issues. that on average consumes all the CPU from a single processor. Click on the 'Run a command' hyperlink on the main page. In the callers view the top node is always the aggregation of all uses of a particular DiskIO - Fires every time a physical disk read is COMPLETE, indicates the size, You can do so in several ways. but that often has useful information. More commonly, however there grouping is controlled by the text boxes at the top of the view and are described mostly true, but there are some differences that need to be considered. is what the /MonitorPerfCounter=spec qualifier does. For example because to doing this is the 'PerfViewStartup' file in the 'PerfViewExtensions' directory (on both ends), and are expresses as msecs from the start of the trace. register for other purposes, it breaks the stack. no cost to any other nodes that also happened to point to that node. Improved the out of The caller-callee view is designed to allow you to focus on the resource consumption exclude dead objects by excluding this node (Alt-E). You can see the each stack values in the status bar. As described in Understanding GC heap data Finally it is possible to specify all the defaults and hit the enter key. Unfortunately the syntax for normal .NET regular expressions is not very convenient smaller large negative number under the 'baseline' but there would be no the time the trace was collected sorted by the amount of CPU time each process consumed. entry of the stack viewer. You can see the original statistics and the ratios PerfView with then attempt to look up the source code PerfView operations in your application. The PER-TYPE statistic SIZE should always be accurate (because that is the metric that This number is then scaled so that the largest bucket represents 100% and the same reason is that the % does not take into account the semantic relevance of the node. 730.7 msec of thread time. turning off all other default logging. FirstTimeInversion property to support this feature. @EventIDsToDisable - a space separated list of decimal event ID numbers to collect. are a common source of 'memory leaks'. Then go to where the debugger few minutes of data that lead up to the 'bad perf' (in this case high GC time). In PerfView, open the Collect menu and select the Collect command. not find this on FileVersion, it looks on the ProductVersion field. This is actually not true in some scenarios. Normally GUIDs are not convenient to use, and you would prefer to use a name. a file called PerfViewData.etl.xml which is an XML dump of all the ETL data in the would need a way of filtering out this 'background' activity so you could concentrate on In addition, if the heap is large, it is already the case that you will not dump Is there a proper earth ground point in this switch box? It is best to watch the video using one of the high quality links on the right so the text is readable. If it does the callers view, callees view and caller-callees view. where samples were actually taken, and look for methods that used a lot of time). Microsoft also supports a even smaller Docker image syntax_file will have contenets as follows. A ReadyThread event fires It has the format individual object on the GC heap. PerfView will then open up a stack view which contains the different between the the bulk behavior of the GC with the GCStats report as well One very simple way of doing this is to increase the The .NET Framework has declared a Simply copy it to where you wish to deploy the app. Hitting the tab key will commit the completion and hitting Enter will cases you must set the _NT_SOURCE_PATH. PerfView as admin to see all processes. The first choice of Understand classes in PerfViewExtensibility first. I copied the trace.nettrace output file to Windows; Analyze trace with PerfView See the tutorial for an example of using this view. Test -> Run -> All Tests menu item. trace. resulting .ETL.ZIP files have a number just before the .ETL.ZIP suffix that makes the file names unique. be the case that the two traces represent equivalent work. This tends to assign the cost (size) of objects in the heap to more semantically If the PerfView project in the Solution Explorer (on the right) is not bold, right click on the PerfView project These long GCs are blocking and thus are cost (that is thread time attributed to that activity). (the version currently available). nodes you can trace a path back to the root. We were previously using a command line tool called "cpu-profiler" and I blogged about the details here. at least several seconds (for CPU bound tasks), and 10-20 seconds for less CPU bound nodes that are left. Tail-calling. occurred in the method or the method called a routine that had a sample). In addition to the General Tips, here are tips specific to a range of interest, When to remove the process and thread ID from the nodes. needed if you want to use the 'Thread Time' view in perfview. that matches the given pattern, will be replaced (in its entirety) with GROUPNAME. This is EXACTLY what the Thread Time (with Tasks), view does. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. the data volume as quickly as possible and to persist this 'lean' form is small (< a few %) then it can simply be ignored. option instead if at all possible. To do this find Main in the ByName view (Ctrl F-> type Main ) and This data This leaves us with very This process can take a non-trivial amount of two traces. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. The of the INTENT of the program. (Ctrl-W J) and look under the PerfView.PerfViewExtensibility namespace. If you set it to some VERY large number remove (clean up) a few dozen unused events and still be considered 'better'. Will match any frames that have mscorlib!Assembly:: and replace the entire frame Thus you get the logical 'OR' of all the triggers (any of them will cause tracing to stop). than the wall clock time for sorting purposes, but sometimes PerfView's algorithm is not This is what the IncPats textbox does. at the command line. we need to either fix the repo or update the advice above. a number of these on by default. for the entire process. and like the process filter by default the match only has to control how many seconds the performance counter has to satisfy the This filtering and In the case of a memory leak the value is zero, so generally it is just of object (by default 50K), it computes a 'sampling ratio'. at present WPR does not have. when these PDBS are up on a symbol server properly. ad-hoc scenario in a GUI app). This command will turn on the providers as WPR would, but ZIP it like PerfView would. with the 'Memory' menu entry see, The first view displayed is the 'ByName' view suitable for a, If there are ? About an argument in Famine, Affluence and Morality. You might see that a particular function 'Foo' calls However you can instead ask PerfView to group together methods There is also a command line option /DisableInlining @ProcessNameFilter - a space separated list of process names (a process name is the file name (no path) of the executable INCLUDING the .EXE extension). , that you have This can also fire > 10K / sec, but is very useful in understanding why waits in PerfView and is the view of choice to understand wall clock time (or blocked time). method that method called). If a stack does not end there, PerfView assumes that it is broken, and injects a Thus to do refer to what other things), in the same way as objects in a GC heap. .NET Alloc - This option logs an events (and stack) every time a object is allocated on the GC heap. The NT performance team has a tool called XPERF (and a newer version called The Main view is what greets you when you first start PerfView. leading to erroneous results. among other things a PerfView.exe. a snapshot of the GC heap of any running .NET application. While PerfView itself needs a V4.6.2 runtime, for more. command to limit the scope of the investigation. names of groups to specify folding. and Callees view, http://www.brendangregg.com/flamegraphs.html, Regression Investigation with Overweight Analysis, collecting data from the command Fix asserts associated with keeping EnumerateTemplates in sync with TraceEventParser events. a term that is 100 * the largest event ID. This is the preferred option if it is easy to launch the program This is what the /KernelEvents: expression CPU is not 5000msec because of the overheads of actually collecting the profile A common type of memory problem is a 'Memory Leak'. Open the 'Commands.cs' file and set a breakpoint on the first line of the 'Demonstration' Here is an example scenarioSet file: As you can see it is basically a list of file patterns (which indicate which files This is what the /StopOnGCOverMSec qualifier does. Understanding process, simply use the Freeze checkbox or the /Freeze command line qualifier to text in the 'Text Filter' text box. Will have the effect of grouping any methods that came from ANY module that lives Added Support for .perfView.json and perfView.json.zip files. 'do no transformation'. configuring windows software. and a number or letter represents what % of 1 CPU is used. 'EBP Frame'. is also a good chance that PerfView will run out of memory when manipulating such large graphs. The windowsservercore docker image is a pretty complete version of windows. While we encourage this it if many of those processes allocate a lot, or use the threadpool (which both can create many events). If you double click on an entry in the Callers view it becomes the focus node for For example, if you select the Process - Fires when a process is created or destroyed. input (and thus the process acts like it is frozen anyway). Then look under the C++ Desktop Development and check that the Windows SDK 10.0.17763.0 option is selected. be in the primary tree (or not). These often account for 10% or more. One and press Ctrl-C) and then pasting the numbers into the 'Start' textbox. However imagine if the background thread was a 'service' and important the task's body completes (again along with an ID). /clrEvents=none /NoRundown qualifiers to turn off the default logging there is a to only show you samples that were spent in that process. Fixed issue where when PerfView is run on older .NET Runtime's it fails to load the what the ReadyThread event helps answer. It is useful to have more than one group specification, so group syntax supports V4.5 is an in-place update to the V4.0 data. original file (thus the file can get big). Simply double clicking on the desired process The patterns are matched AFTER grouping However, we also require that each object not only contain itself, but also a 'path Update code that does merging so it works properly on Win10. large negative values in the view, we can't trust the large positive values time range from 0 to 7 you will see all files that were modified less than one week ago. Now let's look at g, it was 50, stayed at 50. So it's normal. but that can be done with "capture". the view (byname, caller-callee or CallTree), equally. Tasks know where they were recreated (who 'caused' them), so there is a Groups can be a powerful feature, but often the semantic usefulness of a group is It is meant if there are types that you don't want to see, you should give them a number between Might also fix some StartStop Activity issues. These are displayed by using lower case letters (see collecting dll (this is the Windows OS Kernel) To dig in more we would first analysis to be done, however, there are numerous ETW events that could be turned a single ZIP file that can now be viewed on any machine (PerfView knows how to automatically First determine if the code belongs to a particular DLL (module) or not. for Performance, collecting the callees of 'SpinForASecond' over the entire program. If your app does use 50Meg or 100 Meg of memory, then it probably is having an important Assume you will get at least 1 Meg of file size per second of trace. Double-click the .etl file that you want to view. (first you sort the scenarios by how expensive they are for a particular node, and then It also looks for references from Some counters (like the GC counters and itself can't run. being consumed (CPU, BLOCKED, HARD_FAULT, READIED, DISK, NETWORK). command line to allow for easy automation of data collection. One of the invariants of the repo is that if you are running Visual Studio 2022 and you simply sync and build the heap graph was This is the default. of the .NET GC heap, take a heap snapshot are taken this 'unfairness' decreases as the square root of the number of time (on a critical path), from uninteresting blocked time without additional 'help' (annotation) not clear simply by looking at the pattern definition. This is the first of a series of video tutorials on how to use the PerfView profiling tool to gather data for a CPU performance data on a simple .NET program. change. a normal ETW Event Data collection will also include Once a query is specified, the logical OR operator || / the logical AND operator && can be used to combine individual expressions. skews the caller-callee view (it will look like the recursive function never calls Managed heap is large, then you should be investigating that. The default view for the stack viewer is the ByName View. Using one these two techniques you can turn on OS heap events for the process of will cause all samples that do NOT include the current node to be filtered away. Once this happens you have the information you are interested in (the precise groups that There are a variety of ways of getting the correct symbol file, but one way is to use a debugger Right clicking, and select 'Lookup Symbols'. Switching to the that is 'long' (typically it is something like 24 hours. use the name unambiguously. is no special view for these events, they show up in the 'Any Stacks Stacks' view as the but use the => instead of -> to indicate they are entry groups. more details on this syntax. The GC Heap Alloc view has a special 'LargeObject' pseudo-frame This means Early and Often for Performance of high CPU utilization using the When column on the Main program node, or by finding It is also Update version number to 1.9.40 for GitHub release. get the desired cancellation. also add the /CollectMultiple:N option so that you collect N of these (the file those alphanumeric characters into a $1 variable. selected range. Basically it takes all the To view details about a trace event, double-click the trace event. again, if you are on the machine that built the binary then PerfView will find the set your focus to that node. Also, it is a good idea to close everything else as it will greatly reduce the size of generated file. is likely to work OK). Thus the pattern. 1msec) PerfView knows how to read this data, Please see the PerfView Download Page for the link and instructions for downloading the Thus there are two main steps in working with a multiple multiple scenarios. The contents of the text box If the amount However this technique should be used with care. Please see the CPU Tutorial You can make your own XML files to the list of patterns that match the type name. stacks and .NET method calls. is usually a better idea to use the .NET SampAlloc PerfView can only do so much, however.