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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build ignore
Prof is a rudimentary real-time profiler.
Given a command to run or the process id (pid) of a command already
running, it samples the program's state at regular intervals and reports
on its behavior. With no options, it prints a histogram of the locations
in the code that were sampled during execution.
Since it is a real-time profiler, unlike a traditional profiler it samples
the program's state even when it is not running, such as when it is
asleep or waiting for I/O. Each thread contributes equally to the
go tool prof -p pid [-t total_secs] [-d delta_msec] [6.out args ...]
The output modes (default -h) are:
Write the profile information to, in the format used by pprof.
At the moment, this only works on Linux amd64 binaries and requires that the
binary be written using 6l -e to produce ELF debug info.
See for details.
-h: histograms
How many times a sample occurred at each location.
-f: dynamic functions
At each sample period, print the name of the executing function.
-l: dynamic file and line numbers
At each sample period, print the file and line number of the executing instruction.
-r: dynamic registers
At each sample period, print the register contents.
-s: dynamic function stack traces
At each sample period, print the symbolic stack trace.
Flag -t sets the maximum real time to sample, in seconds, and -d
sets the sampling interval in milliseconds. The default is to sample
every 100ms until the program completes.
It is installed as go tool prof and is architecture-independent.
package main