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Diffstat (limited to 'src/cmd/prof/doc.go')
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diff --git a/src/cmd/prof/doc.go b/src/cmd/prof/doc.go new file mode 100644 index 000000000..2640167d3 --- /dev/null +++ b/src/cmd/prof/doc.go @@ -0,0 +1,49 @@ +// 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 +statistics. + +Usage: + go tool prof -p pid [-t total_secs] [-d delta_msec] [6.out args ...] + +The output modes (default -h) are: + + -P file.prof: + Write the profile information to file.prof, 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 http://code.google.com/p/google-perftools 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 |