tools/perf/Documentation/perf-trace.txt

   1 perf-trace(1)
   2 =============
   3
   4 NAME
   5 ----
   6 perf-trace - strace inspired tool
   7
   8 SYNOPSIS
   9 --------
  10 [verse]
  11 'perf trace'
  12 'perf trace record'
  13
  14 DESCRIPTION
  15 -----------
  16 This command will show the events associated with the target, initially
  17 syscalls, but other system events like pagefaults, task lifetime events,
  18 scheduling events, etc.
  19
  20 This is a live mode tool in addition to working with perf.data files like
  21 the other perf tools. Files can be generated using the 'perf record' command
  22 but the session needs to include the raw_syscalls events (-e 'raw_syscalls:*').
  23 Alernatively, the 'perf trace record' can be used as a shortcut to
  24 automatically include the raw_syscalls events when writing events to a file.
  25
  26 The following options apply to perf trace; options to perf trace record are
  27 found in the perf record man page.
  28
  29 OPTIONS
  30 -------
  31
  32 -a::
  33 --all-cpus::
  34         System-wide collection from all CPUs.
  35
  36 -e::
  37 --expr::
  38         List of events to show, currently only syscall names.
  39         Prefixing with ! shows all syscalls but the ones specified.  You may
  40         need to escape it.
  41
  42 -o::
  43 --output=::
  44         Output file name.
  45
  46 -p::
  47 --pid=::
  48         Record events on existing process ID (comma separated list).
  49
  50 -t::
  51 --tid=::
  52         Record events on existing thread ID (comma separated list).
  53
  54 -u::
  55 --uid=::
  56         Record events in threads owned by uid. Name or number.
  57
  58 -v::
  59 --verbose=::
  60         Verbosity level.
  61
  62 -i::
  63 --no-inherit::
  64         Child tasks do not inherit counters.
  65
  66 -m::
  67 --mmap-pages=::
  68         Number of mmap data pages (must be a power of two) or size
  69         specification with appended unit character - B/K/M/G. The
  70         size is rounded up to have nearest pages power of two value.
  71
  72 -C::
  73 --cpu::
  74 Collect samples only on the list of CPUs provided. Multiple CPUs can be provided as a
  75 comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
  76 In per-thread mode with inheritance mode on (default), Events are captured only when
  77 the thread executes on the designated CPUs. Default is to monitor all CPUs.
  78
  79 --duration:
  80         Show only events that had a duration greater than N.M ms.
  81
  82 --sched:
  83         Accrue thread runtime and provide a summary at the end of the session.
  84
  85 -i
  86 --input
  87         Process events from a given perf data file.
  88
  89 -T
  90 --time
  91         Print full timestamp rather time relative to first sample.
  92
  93 --comm::
  94         Show process COMM right beside its ID, on by default, disable with --no-comm.
  95
  96 -s::
  97 --summary::
  98         Show only a summary of syscalls by thread with min, max, and average times
  99     (in msec) and relative stddev.
 100
 101 -S::
 102 --with-summary::
 103         Show all syscalls followed by a summary by thread with min, max, and
 104     average times (in msec) and relative stddev.
 105
 106 --tool_stats::
 107         Show tool stats such as number of times fd->pathname was discovered thru
 108         hooking the open syscall return + vfs_getname or via reading /proc/pid/fd, etc.
 109
 110 -F=[all|min|maj]::
 111 --pf=[all|min|maj]::
 112         Trace pagefaults. Optionally, you can specify whether you want minor,
 113         major or all pagefaults. Default value is maj.
 114
 115 --syscalls::
 116         Trace system calls. This options is enabled by default.
 117
 118 PAGEFAULTS
 119 ----------
 120
 121 When tracing pagefaults, the format of the trace is as follows:
 122
 123 <min|maj>fault [<ip.symbol>+<ip.offset>] => <addr.dso@addr.offset> (<map type><addr level>).
 124
 125 - min/maj indicates whether fault event is minor or major;
 126 - ip.symbol shows symbol for instruction pointer (the code that generated the
 127   fault); if no debug symbols available, perf trace will print raw IP;
 128 - addr.dso shows DSO for the faulted address;
 129 - map type is either 'd' for non-executable maps or 'x' for executable maps;
 130 - addr level is either 'k' for kernel dso or '.' for user dso.
 131
 132 For symbols resolution you may need to install debugging symbols.
 133
 134 Please be aware that duration is currently always 0 and doesn't reflect actual
 135 time it took for fault to be handled!
 136
 137 When --verbose specified, perf trace tries to print all available information
 138 for both IP and fault address in the form of dso@symbol+offset.
 139
 140 EXAMPLES
 141 --------
 142
 143 Trace only major pagefaults:
 144
 145  $ perf trace --no-syscalls -F
 146
 147 Trace syscalls, major and minor pagefaults:
 148
 149  $ perf trace -F all
 150
 151   1416.547 ( 0.000 ms): python/20235 majfault [CRYPTO_push_info_+0x0] => /lib/x86_64-linux-gnu/libcrypto.so.1.0.0@0x61be0 (x.)
 152
 153   As you can see, there was major pagefault in python process, from
 154   CRYPTO_push_info_ routine which faulted somewhere in libcrypto.so.
 155
 156 SEE ALSO
 157 --------
 158 linkperf:perf-record[1], linkperf:perf-script[1]