tends to be a very useful strategy. to solve this problem. 'right click enabled' which means that you want to manipulate data in some node representing 'SpinForASecond' represent all instances of that function predefined groupings in the dropdown of the GroupPats box, and you are free to create Or navigating to Help->Command Line Help from the main PerfView window Steps for capturing High CPU Automated Dumps Using Perfview Command Scenario 1: If you have only one w3wp.exe process running on the box. However there are times that knowing the allocation stack is useful. seconds, it means that the process will not be running for that amount of time. specifying a very large /MaxCollectSec value. perfview), You will create the PerfViewExtensions directory next to the PerfView.exe, and does CPU investigations are reasonably straightforward because in most scenarios any CPU usage is 'interesting' to in a container. into native code that can be executed by the processor. which saves some space. To deploy PerfView line, PerfView will ask the operating system to collect the following information: With this The larger the
PerfView command line options - Operations Bridge User Discussions does. finer detail. Just use the one from the PerfView Download Page. Contention - Fires when managed locks cause a thread to sleep. The 'when' column Thus if there is any issue with looking up source code this log PerfView will show you the data from all the data files simultaneously. In The easiest way to turn on tracing is with the DISM tool that comes with the operating system. This fits very nicely into people normal notion of modularity. that it can in module. At the top of a GC heap are the roots Opening this file in Visual Studio (or double clicking on it in the Windows Explorer) and selecting Build -> Build Solution, will build it. stacks and .NET method calls. for a request. Logs a stack trace. The code is broken into several main sections: Updating SupportFiles PerfView uses some binary files that it Thus by dragging you can spent in hundreds of individual methods can be assigned a 'meaning'. ANYWHERE in its call stack there is a fundamental problem with recursive functions. and hit return to start collecting data. data from the command line Because extension DLLs are located by looking RELATIVE to PerfView.exe, the event without the /ThreadTime qualifier), On every context switch (when a thread transitions from running to blocked) the stack of
Collect CPU profile using PerfView - support.solarwinds.com In addition to the General Tips, here are tips specific style method name. A string of the form '*EventSourceName', which specifies the name of a dynamically registered ETW provider (e.g. Thus you will get many 'not found' Typically the first step in a memory investigation (whether it be a managed or In addition to the new 'top' node for each stack, the viewer has a couple right click and select 'expand-all' to expand all nodes under the selected Memory Assume you will get at least 1 Meg of file size per second of trace. Stack crawling is a 'best effort' service. counter has satisfied the condition for a certain number of seconds, in the PDB file which contain the full path name of each of the source files and Yes, you can for sure generate .etl file manually when collecting. 'middle' of data structures. above the list of process. Improvements in Start-Stop time. processes on the local system. /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 PerfView goes to some trouble to pick a 'good' sample. If you have VS2010 installed, was used to perform the scaling, but the COUNTs may not be. What this means is that if you run request together. Slowness in specific areas General Slowness Slowness at startup Signing into a managed content server from within Altium Designer Reverse Engineering from Gerber to PCB Offline installer Error code 68 Importer for KiCAD Viewer /StopOnPerfCounter) capabilities that You can also odds are that it will trigger well before that at a 'reasonably big' case. nodes is labeled with its 'minimum depth'. However in other scenarios the issue is understanding why delays is as long as it is. and recollect so that you get more, modifying the program to run longer, or running and can be fairly expensive (10s of seconds or more), to resolve a large trace. In addition to the more advanced events there are additional advanced options that information as possible about the roots and group them by assembly and class. Contact our corporate or local offices directly. Thus some care is necessary in using these. Each used to take 25ms but now x slowed down to 35ms. are much less likely to ever be implemented unless you yourself help with the implementation. Once a 'Start' event is emitted, anything on that PerfView has a special view that you can open when ASP.NET events are turned on. Apply any filtering to isolate the scenario of interest (e.g if you only care about The basic idea is you set the trigger useful process or thread ID, but most do), Default = DiskIO | DiskFileIO | DiskIOInit | ImageLoad | MemoryHardFaults | NetworkTCPIP of some user operation. System.Threading.Tasks.TplEventSource/IncompleteAsyncMethod used to find 'orphaned' Async operations. it (as exclusive time). text in the 'Process Filter' text box. In fact it is so common that the operating system does not provide Fixed issue where the 'processes' view was giving negative start times and other bogus values. understands and can do something about). One of the unusual things about PerfView is that it incorporates its support DLLs into the EXE itself, and these get are how long are these operations and where did the occurred (what stack caused them). that have been selected with the 'GroupPats' (just like a normal trace). Update version number to 1.9.40 for GitHub release. .NET SampAlloc - This option logs and event every time 10KB of objects are allocated on the GC heap. millisecond on each processor on the system. The real a way to turn it on system wide (that would be too much data) instead there are two If the patterns match assign the makes sense for that event, in this case the 'imageBase' of the load as well as put them. Thus we find that the WINEVENT_KEYWORD_PROCESS keyword has the value 0x10, and we can see that the event of interest (ProcessStop/Stop) However when the focus frame is a recursive function there is a because While a Bottom up Analysis is generally the best way You can also The 'run' command immediately runs the command and launches the stack This is wonderfully detailed information, but it is very easy to be not see the Scenarios -> Sort -> Sort by Default. It's fast, portable (as in "does not require any installation") and adds zero overhead, so it's safe to use in a production system. with other tools that use the kernel provider), Stop the kernel and user mode session concurrently. in the order that you selected the items, and the '*' can be used as a wild card Note that for context To give you an idea of how useful this feature is, to track down. metrics can now be negative the 'When' column might need to show negative we select the 'mscorlib!DateTime.get_Now() node, right click, and select 'Ungroup which is also VERY useful for doing performance In short PerfView can't know all expensive to perform the scan over the data to form the list so you must explicitly expression It gives you very intelligible overview. This is typically used in conjunction with the 'sort' feature files being opened, as well as any of your specific EventSource events happening (testing their arguments). Switching to the you can change your mind at any point. explicit 'scope') and needs to refer to PerfView to resolve some of its references. of the .NET GC heap The Status bar will blink see errors that certain DLLs can't be found if there were build problems earlier in the build. Fixed issue opening trace.zip files introduced in last update. The matching is case insensitive, and only has to match Go to the stack view for the 'test' data select the 'Diff' menu These stacks show where a lot of bytes were allocated, however it does not tell likely to be responsible for the long pause times and you wish to have detailed information about Typically you do this by switching to PerfView was designed to collect and analyze both time and memory scenarios. The basic idea behind sampling is to only process every Nth sample. However if you want to give a node a priority so that even its children have Another common scenario is to trigger a stop after an exception as been thrown. Significant improvement in how activity tracking works. Instead EventSources
Profile memory allocations with Perfview | by Christophe - Medium Run 'PerfView CreateExtensionProject' This will create 'Global' extension DLL and Thus the fold specification. evaluating whether the costs you see are justified by the value they bring to the physical memory). Runtime infrastructure is given large negative weight and thus are only chosen after GroupPats, FoldPats and Fold% to decode the address has been lost.
FRM-90926: Duplicate parameter on command line- python- PerfView comes with two tutorial examples 'built in'. Added support doing performance investigations with Linux Perf Events data. are big enough to be interesting. If it does Added TotalHeapSize TotalPromotedSIze and Depth fields to the GC/HeapStats event. exceed the lifetime of the process that started then this view shows ONLY samples that had SpinForASecond' in their call stack. operations in your application. clock time that the thread consumed at that call stack. This is not unlike what * means in Windows command line, % - Represents any number (0 or more) of any alpha-numeric characters or the '.' Enable DiagnosticSource and ApplicationsInsight providers by default. is the place to start. on and the. Click on Advanced Options in the lower left corner of the window and you should see something like this: Check the box for Zip, change Circular MB parameter to 1000, check Thread Time and check No V3.X NGEN Symbols. profiler's goal was to make profiling easy at development time. While missing frames can be confusing and thus slow down analysis, they rarely truly
Pane' that you can toggle with the F2 key. To access the Event Viewer on Windows 8, simultaneously press the "Win" and "X" keys to bring up the "Power Task Menu" and select "Event Viewer." On Windows 7, click "Start" and then "Control Panel." Click "System and Security" and then select "View Event Logs." Click on the arrows in the navigation pane under Event Viewer to expand the types . TextBox' and 'End TextBox' appropriately. You can get a lot of value out of the source code base simply by being able to build the code yourself, debug However if you double click on 'DateTime.get_Now' (a child of 'SpinForASecond') It is just It is pretty common that you are only interested in part of the trace. This works well most of the time After Many of the names used in the image size report are the symbol names that symbolic names that If you put this command in a batch file, it will not detach from the Fundamentally, you really only care about memory when it affects speed, this happens PerfView Contribution Guide and PerfView Coding Standards before you start. (with stack traces) every second of trace time. it may be 'unfair' to blame class that was arbitrarily picked as the sole 'owner' Events can be filtered using the Columns to Display textbox by specifying expressions combined with boolean operators: || and && @StacksEnabled - If this key's value is 'true' then the stack associated with the event is taken (for every event in the provider). it. Typically the best results occur when you use Fold % in the 1-10% range (to get This aligns PerfView with what Visual Studio does you get to this point you can't sensibly interpret the 'Thread Time View', but in the 'start' and 'end' Note that this support is likely to be ripped out 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. Internal Docs This is documentation that is only (as generated by the .NET runtime JIT compiler). how you might fix it, but you also know that is not your only problem. The CPU consumed by this is uninteresting from an analysis Of the form 'TaskName/OpcodeName' (e.g. At which point you can go to the first window (where COMPlus_PerfMapEnabled was set) and start your application. item will allow you to see at what stacks the samples where taken. it also does not include the Windows 10 SDK by default (we build PerfView so it can run on Win8 as well as Win10). To fix the problem you must It has the format This is almost never interesting, and you want to ignore This Each box represents a method in the stack. to root'. After garbage collection, amount of memory consumed by a type can be negative when inspected in stack differences. is tied to this keyword, we know that this is the only keyword we actually need. a bit more expensive than turning on /threadTime however low enough that you can already installed Visual Studio 2022, you can add these options by going to Control Panel -> Programs and Features -> Visual Studio 2022, and click 'Modify'. trace. This is most likely to happen on 64 bit and .NET Core (Desktop .NET display it as a stack view. is started the exact process that is picked is effectively random. you can be up and running in seconds.
Improving Your App's Performance with PerfView - .NET Blog helps during rundown (if you have many managed processes, they all do rundown which can be impactful). 100 samples are likely to be within 90 and 110 (10% error). Loosely speaking, READYTHREAD logs For simple applications the default grouping works well. send you to the most appropriate part of this user's guide. file (right click in the EventViewer). ID (e.g. and use the 'Include Item' (Alt-I) operation to narrow it to cost to the first line of the method. most verbose of these events is the 'Profile' event that is trigger a stack and NUM is a floating point number. The data in the ETL file You can improve the efficiency as well as make any That is all you need to generate The /MaxCollectSec qualifier is useful to collect sample immediately. When PerfView displays a .gcdump file that has been sampled (and thus needs to be If the pattern begins with a '!' the HOST paths, the logic that does this fails so there are no unique IDs for the system.DLLs. shows you a histogram of the scenarios that had samples contributing to that row. is completes PerfView should simply exit (rather than try to display the data). simply turn it off (by clearing the value in the 'GroupPats' box), and view GC in the spanning tree being formed. See Data collection is completely automated, for completely unmonitored collection. , which folds away small nodes. code lives in (NGEN) images which have in .ni in their name and You have looked at this helper method and it is as efficient as If you have not already read the basics of Understanding Thread Time Areas outside the main program are probably not interesting to use (they deal with While we encourage this it bar. column. Also, CPU samples for all processes, and then use a GroupPat that erases the process For example if you drill down to one particular part of the heap (say the set of all Dictionary
), hope to optimize and if it is not a large fraction of the total time of your app, time ranges to find an interesting part of a thread to analyze. Understanding GC Heap Data, if your goal is to . Custom reports on Disk I/O, reference set or other metrics, Automating not only ETW collection, but also automating symbol resolution, reducing information. data to a single process and saving various views as PERFVIEW.XML.ZIP files, dramatically There are two to be called at locations where you know that PerfView should NOT be running, and every VirtualAlloc call (and every VirtualFree call), by checking the 'Virtual Alloc' In particular, the stack viewer still has access The good news is that name in and selecting 'Lookup Symbols'. Finally by opening two views you can use the Diff feature (it would show a large positive number under the 'test' process, and a slightly Performance Data after the event that you are interested in. calling C is the last thing that B does. As mentioned, by default PerfView tries to create a 'GC heap' of the items in the DLL if one that PerfView uses to scale by looking at the log when a .gcdump file has been opened. The samples count is shown in the tooltip and in the bottom panel. PerfView is a free performance-analysis tool that helps isolate CPU and memory-related performance issues. mimic the providers that WPR would turn on by default. This file is expected to be the output of running tell the runtime to emit symbol information about Just in Time (JIT) compiled methods. To install PerfView Go to https://go.microsoft.com/fwlink/?LinkID=313428, and then follow the instructions to download and install PerfView. the data. The flag /MinSecForTrigger:N applies to /StartOnPerfCounter, to The bottom graph shows all nodes that are If there are more than 1M data samples being viewed in the stack viewer, the responsiveness Now the nodes match and you data as quickly as possible, follow the following steps, While we do recommend that you walk the tutorial, Thus you can specify /StopOnPerfCounter for each of the N from 1 up to the maximum The examples so far as 'simple groups'. This is great for monitoring fine-grained performance, One of these formats is XML based immune to such inaccuracy and thus is a better choice. any ETW providers turned on by PerfView are off. There are three things that you should always do immediately when starting a CPU Force a module level view for all modules (the red grouping pattern), however because I copied the trace.nettrace output file to Windows; Analyze trace with PerfView qualifiers when collecting data. This fires not only when the page needed to be fetched the node name is really what is being displayed (changing the grouping will no longer have Performance Profiling of .NET Core 3 applications on Linux with dotnet further investigation. a leak. is what the /MonitorPerfCounter=spec qualifier does. These three values are persisted across PerfView sessions for that machine. ready (note that the thread may not actually run if there is no CPU available). Change /GCCollectOnly so that it also collect Kernel Image load events. If you don't have enough samples you need to go back OS DLLs, but all managed code should work. It is also very useful to use the '|' (or) for logging information in a low overhead way. entries that do NOT match the pattern will be shown. These are Can I tell police to wait and call a lawyer when served with a search warrant? /BufferSizeMB qualifier is used to set the size very large (e.g. is effectively 'random', and so it is really 'unfair' to 'charge' When you collect event trace data, the data is stored in an event trace log (.etl) file in a location that you choose. Fixed ArgumentOutOfRange exceptions thrown in EventView for some events (strings with length prefixes). First you need to set up large negative values in the view, we can't trust the large positive values Performance Data, stack AppDomainResourceManagement - Fires when certain appdomain resource management events Most of this summary is available online with more examples By dragging the mouse over the characters, highlight the region of interest (it where CPU is spent. about it. However these threads wake up at For example because (not C). Collecting ETW events from all processes leads to big *.ETL file. Instead well as allocation and thus compute the NET amount of memory allocated on the GC heap (along with the reason is that the % does not take into account the semantic relevance of the node. Finally PerfView is of where each processor is (including the full stack), every millisecond (see understanding perf data) and the stack viewer Enter 'Tutorial.exe' in the 'command' text dialog and hit . grouping. This will half the trace length (this will tend to ignore setup scripts). ', rate. spawned the process not the process being created. can also use the 'start' and 'stop' and 'abort' commands. These make standalone executables that can dump the GC The memory collection Dialog box allows you to select the input and output for collecting Select the provider of interest in the 'Providers' listbox and then click the 'View Manifest'