The developer docs: ; The output of go tool pprof –help (I pasted the output on my. Step #5: run go tool pprof. Pass your binary location, and the location of the cpu. pprof file as returned when running your program. You can. To build and install it, use the go get tool. go get -u Remember to set GOPATH to the directory where you want pprof to be installed.

Author: Zuzuru Mojas
Country: France
Language: English (Spanish)
Genre: Spiritual
Published (Last): 8 June 2012
Pages: 465
PDF File Size: 13.83 Mb
ePub File Size: 8.18 Mb
ISBN: 355-6-95856-811-6
Downloads: 74290
Price: Free* [*Free Regsitration Required]
Uploader: Dogrel

From there you can visit its callers by clicking its declaring func token.

Pprfo takes an even number of strings representing key-value pairs and makes a LabelSet containing them. A sample is a stack trace, and this stack trace has 2 locations: Fatal “could not start CPU profile: The first step to profiling a Go program is to enable profiling.

It was generating these heap profiles named like pprof. There may be non-exported or anonymous functions among them if they are called dynamically from another package. We can run the profiler again g confirm that main.

pprof – The Go Programming Language

Packages can create and maintain their own profiles; the most common use is g tracking resources that must be explicitly closed, such as files or network connections. WriteHeapProfile is shorthand for Lookup “heap”.


In all but one of the cases where maps are being used, it is impossible goo the algorithm to insert a duplicate element. There’s no reason fo use a map when an array or slice will do. ForLabels invokes f with each label set on the context. Terms of Service Privacy Policy View the source code. When understanding how things work I like to start at the beginning.

The root nodes are the entry points of the package: DFS first, just because it is a shorter function:. Excluding the recursion, it looks like the time is going into the accesses to the number map on lines, and Context, labels LabelSet, f func context. In the prpof remaining case, we can write a simple variant of the append built-in function:. The Go Programming Language. WriteTo writes a pprof-formatted snapshot of the profile to w. Request func Profile w http.

Each Hool has a unique name. Just as they would be in a compiler, the basic block structures have unique sequence numbers assigned to them. The output of this is a bit long, you can view it all here: FindLoops pprof top5 -cum. Then when it comes time to analyze your memory usage, you can decide where you want inuse memory or total allocation counts!

Profiling Go programs with pprof

The Go yo presented in that paper runs quite slowly, making it an excellent opportunity to demonstrate how to use Go’s profiling tools to take a slow program and make it faster. Do calls f with a copy of the parent context with the given labels added to the parent’s label map.


Such a global variable is bad engineering practice, of course: The third column shows the running total during the listing: In fact, in Hundt’s paper, he explains that the Java program needed just this change to get anything like reasonable performance, but he did not make the same change in the other garbage-collected implementations. Click a node to visit that function’s source code. For now, we are making the minimal possible changes in order to understand what is important for the performance of our program; this change is simple and mirrors the code in the Java implementation.

This contains 1 sample. So the stack traces in the heap profile might be for code that is not running anymore — like maybe a function allocated a bunch of memory, returned, and a different function that should be freeing that memory is misbehaving. Trace responds with the execution trace in binary form. Similarly, the loop graph storage can be reused on each iteration instead of reallocated. Writer, debug int error Bugs.