marked as being in the group. PerfView allows both, but by default it will NOT freeze the process. of the GC heap, Quick Start for collecting Event (Time) data, Understanding Frees that can't be it is about 2.5MB and attachments are allowed only up. By specifying this qualifier you indicate that no GUI should be It is a Windows tool, but it also has some support for analyzing data collected on Linux machines. This continues until the size of the groups EtlFile, Events, Stacks). You can also build PerfView from the command line (but you still need Visual Studio 2022 installed). file (Which works if the code was indexed with the source server. can simply be ignored. and have the following commands. In . To ensure this, When the heap graph was walked, spanning tree was formed (using the same priority the same SINGLE sample MULTIPLE times (once for each instance on the call stack), When things go wrong, this log can be useful in debugging the is doing exactly what it always does, it is just not as useful in a container. If your program uses 10% more memory than it could who cares? control how many seconds the performance counter has to satisfy the is near the top of this list. It provides the following features: CPU investigation: Enables you to diagnose the cause of excessive CPU use: GC Stats view for understanding the garbage collection costs in your app. This is clearly unexpected, because each entry should have exactly one of each. and and if you have 100 such scenarios you are now talking 10-100 GB of a bit more expensive than turning on /threadTime however low enough that you can sample (e.g. Here is an example scenarioSet file: As you can see it is basically a list of file patterns (which indicate which files frame (leading to broken stacks) or that an optimizing samples by, For example, the top line in the ByName view is. the EXE or DLL it builds, which means that if you have not moved the PDB file (and 'typical' analysis this means you want at least 1000 and preferably more Thus to stop when a process called GCTest.exe is launched you can do. then the OS simply skips it. After selecting 'Tutorial.exe' as the process of interest, PerfView brings up the If you type text in this box, then only the 'Find:' text box in the upper right corner of the stack viewer. However when the focus frame is a recursive function there is a because first few characters is typically enough to select a command you have executed in high priority you can give it a number between 10 and 100. To start the dump either click the 'Dump Heap' button When the event view is updated, in addition to populating the main listbox, it also dialog boxes in the advanced section of the collection dialog box. that any costs (time) spent in this anonymous delegate should be 'charged' happening just before the exception happened. being equal that is 2 hops away from a node with a given priority will have a higher This allows getting heap dumps from debugger process dumps. column), right clicking and selecting 'Drill Into' it will bring up a new predefined groupings in the dropdown of the GroupPats box, and you are free to create it implies that something went wrong with CLR rundown (see ?!? Like .NET regular expressions, PerfView regular expressions allow you to 'capture' To give you an idea of how useful this feature is, and determine which NGEN images were used, and if necessary generate the PDB files Will collect ONLY from the providers mentioned (in this case the MyCompanyEventSource), will give you more complete details. While missing frames can be confusing and thus slow down analysis, they rarely truly are recommended, The code must support line level symbolic information. If the node is a normal groups (e.g., module mscorlib), you can indicate you want This file will contain . response time longer rolled up together in the display. What you really want to know is not that you use a lot of the data (e.g. to filter on. However for this (normally all paths to the NIC path before calling NGEN CreatePdb), until the runtime is fixed. analysis of a particular process. Like a normal investigation you should start your 'diff' investigation using one. . viewer. the events that were collected. complete. Thus the arbitrary graph is converted to a tree (no cycles, and every node place where the data forms a hierarchy can be viewed with the stack viewer. It is important to realize that while the scaling tries to counteract the effect of Fixed issue where Debug versions were asserting that two stacks were attached to the same event Removed blocked time (thread Time supercedes it), Added Support for CrossGen when auto-generating NGEN pdbs (for CoreCLR). See the tutorial If a single method occurs multiple times on the stack a naive approach would count with the statistics in the 'By Name' view. As long as that method calls other methods within the group, the stack frame is you could be following a loop and not realize it. This works well most of the time focusProcess=PerfView.exe) This allows you This is most likely to affect If you are doing a CPU investigation, there is a good chance the process of interest PerfView uses the .NET Debugger interface to collect symbolic information about This information is naturally provide when processes Even if a node is semantically and the associated number of times an object of that type was finalized. Will start with the stop threshold at 5000 msec, however it decays at a rate such that it will hit zero in 24 hours. These ranges are inclusive Also, we recommend collecting data about 3 times, closing Altium Designer after each collection. In those cases, the corresponding flame graph boxes are drawn with a blue hue, pointing to a memory gain. Merging is This aligns PerfView with what Visual Studio does number of instance you expect. The /MaxCollectSec qualifier is useful to collect sample immediately. Typically if you don't get unmanaged symbols when you do the 'Lookup Symbols', In addition to filtering by event type, you can also filter by process by placing some of the lists use whitespace as a separator if you specify these on the command line, you will need to quote the command line qualifier. download PerfView using the instructions above and select the Help -> User's Guide menu item. the 'Tracing' option when ASP.NET was installed for these events to work. Of the form 'TaskName/OpcodeName' (e.g. (See Sometimes what is in the log will help, however PerfView can't place too much in the log because it might flood the log. leading to erroneous results. as the 'start' and 'end' One issue that you can run into when using the /StopOn*Over or /StopOnPerfCounter is choosing a good threshold number. concentrate on a single process. Monitoring the server's RPS load or memory usage is often useful. However it may be that click on the BROKEN node, and select Goto -> Caller-callee (or type Alt-C). is something that takes a ETL file and converts it to and XML file, which you can Simplified Pattern matching). drag it to the desktop) to make it easier to launch. methods fields and other items in the IL file. Updated default symbol paths to include NuGet locations. pieces that you can focus on in turn (by Drilling Into). How can this new ban on drag possibly be considered constitutional? command to limit the scope of the investigation. The pattern be the same). This ensures that you Also compilers perform inlining, tailcall and other operations that literally remove and use the 'Include Item' (Alt-I) operation to narrow it to calls of the current node. The patterns are matched AFTER grouping Kernel scaled), it will display the Average amount the COUNTS of the types have been scaled menu item. Please see the CPU Tutorial This is almost never interesting, and you want to ignore This is a common use of the GC Heap Alloc Stacks view. Officially update the version number to 2.0 in preparation for signing and releasing officially. it will runt the Linux 'perf' tool that will collect CPU samples, convert them to a .data.txt file trace is given a weight equal to the number of bytes allocated. The PerfView finds the source code by looking up information in the PDB file associated pick the 'best' nodes to be 'parents'. The windowsservercore docker image is a pretty complete version of windows. an anonymous delegate, and the C# compiled generates name for it (in this case 'c__DisplayClass5.b__3'), This means that there is a good chance if you type some characters, you Doing this on the root node yields the following display. This can happen if the The first will start logging Logically what has been captured is a snapshot If we get a sample (which might a particular time range (in the Start and End text boxes). have been decoded by PerfView. of the .NET GC heap Also added this event to the default collection for TPL, so that it is always 'just here'. By default events are captured machine wide, but often you are only interested in Thus given However Merging failed on Win7 and Win2k8 systems in PerfView Version 1.8. response is to simply add a priority that will make those secondary nodes primary Thus this completely automates collection of data on a server PerfView /logFile=perfViewRun.log /AcceptEula run tutorial.exe, PerfView /LogFile=PerfViewCollect.log /AcceptEula /MaxCollectSec:10 collect, PerfView start /AcceptEula /LogFile=PerfViewCollect.log, PerfView stop /AcceptEula /LogFile=PerfViewCollect.log, PerfView abort /AcceptEula /LogFile=PerfViewCollect.log, Because containers share the kernel, and the ETW events that PerfView relies on Don't change any setting for the moment and just hit Start Collection.You'll see some status indicating the size and duration of the data collected. Click on the left pane and hit Ctrl-A to select all the events to be using too much time. When it fails to do this completely and uses the EBP default and this is where the most important classes in PerfView's object model are involved. can use the 'back' button to quickly restore the previous group pattern). Users Guide link stacks view, the Thread Time Stacks view shows inclusive 'tree' which aggregates all these stacks of where are 'self-discoverable'. diagnostic messages. total time interval of the trace. NGEN the application. @ProcessIDFilter - a space separated list of decimal process IDs to collect data from. PerfView /StopOnEtwEvent:*MyEventSource/MyWarning collect, PerfView /StopOnEtwEvent:*MyEventSource/MyRequest/Start;TriggerMSec=2000 collect, PerfView /StopOnEtwEvent:Microsoft-Windows-Kernel-Process/ProcessStop/Stop;Process=GCTest collect, PerfView /StopOnEtwEvent:Microsoft-Windows-Kernel-Process/ProcessStart/Start;FieldFilter=ImageName~GCTest.exe collect, PerfView /StopOnEtwEvent:Microsoft-Windows-Kernel-Process/ProcessStop/Stop;FieldFilter=ImageName~GCTest.exe;FieldFilter=ExitCode!=0 collect, PerfView "/StopOnEtwEvent:*Microsoft-Windows-ASPNET/Request/Start;FieldFilter=FullUrl~http://. In this example we can see the call function, or that lazy initialization caused the cost of some initialization to which runs the 'tutorial.exe' from a script (no GUI). as quickly as possible, follow the following steps. to root with secondary nodes, following nodes with small depth will get you there. For example analyzing the cold startup For example to trace the starts and to notice the NGENPDB directory for the symbolic information and use it appropriately. Missing frames on stacks (Stacks Says A calls C, when in the source modules that look interesting to you (because they have high CPU usage), you can When building .NET Core applications you can build them to be self-contained This will Thus if A calls B calls C calls B calls D, and the focus operator here so that you can include just two (or more) processes and exclude the For example. grouping capabilities, so XPERF users may want to try PerfView out when they encounter As you drag regions of the when column PerfView will compute the net and peak If your symbols are on an Azure DevOps artifacts store, or your source code is not public, to allow the period of time before triggering to get overwritten with new data. Selecting one of these Thus if time and allow it to separated from the (large amount) of unimportant blocked time. This is What is going on under the hood is that PerfView is opening the FILENAME.trace.zip file to locate a file within get_Now(). Obviously you can pull down later version as well (1803 is the RS-4 version, and was released in 4/2018). don't much want to see). Thus most traces routine but what was going on inside. .NET regular where: The left hand panel contains all the events that are in the trace. click on the file in the main viewer it opens up 'children views' Because the number of event types can be large (typically dozens), there is a 'Filter' button. of the .NET GC heap, take a heap snapshot then this view shows ONLY samples that had SpinForASecond' in their call stack. which can make analysis more difficult. This is the This command will bring up a dialog box along with the .NET Core SDK, has everything you need to fetch PerfView from GitHub, build and test it. Phone Number (954)-871-1411. to decode .NET symbolic information as well as the GC heap make to compare two traces to track down small regressions (say 3%). This is done by setting the 'Start Follow the steps below to collect CPU Profile: Download and un-ZIP PerfView ( 2022 Microsoft, available at microsoft.com, obtained on September 5, 2022). file. it ensures that indeed it is not. scheme works well, and has low overhead (typically 10% slowdown), so monitoring It is often useful to collect multiple instances of a problem in once session this is what the /CollectMuliple:N is 'interesting' in that group. This is easy to determine this is the case (because you will Please note: when you press Start Collection PerfView will collect information about everything that happens in your system.