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 Alternatively, '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 syscalls 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 --filter-pids=::
  59         Filter out events for these pids and for 'trace' itself (comma separated list).
  60
  61 -v::
  62 --verbose=::
  63         Verbosity level.
  64
  65 -i::
  66 --no-inherit::
  67         Child tasks do not inherit counters.
  68
  69 -m::
  70 --mmap-pages=::
  71         Number of mmap data pages (must be a power of two) or size
  72         specification with appended unit character - B/K/M/G. The
  73         size is rounded up to have nearest pages power of two value.
  74
  75 -C::
  76 --cpu::
  77 Collect samples only on the list of CPUs provided. Multiple CPUs can be provided as a
  78 comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2.
  79 In per-thread mode with inheritance mode on (default), Events are captured only when
  80 the thread executes on the designated CPUs. Default is to monitor all CPUs.
  81
  82 --duration:
  83         Show only events that had a duration greater than N.M ms.
  84
  85 --sched:
  86         Accrue thread runtime and provide a summary at the end of the session.
  87
  88 -i
  89 --input
  90         Process events from a given perf data file.
  91
  92 -T
  93 --time
  94         Print full timestamp rather time relative to first sample.
  95
  96 --comm::
  97         Show process COMM right beside its ID, on by default, disable with --no-comm.
  98
  99 -s::
 100 --summary::
 101         Show only a summary of syscalls by thread with min, max, and average times
 102     (in msec) and relative stddev.
 103
 104 -S::
 105 --with-summary::
 106         Show all syscalls followed by a summary by thread with min, max, and
 107     average times (in msec) and relative stddev.
 108
 109 --tool_stats::
 110         Show tool stats such as number of times fd->pathname was discovered thru
 111         hooking the open syscall return + vfs_getname or via reading /proc/pid/fd, etc.
 112
 113 -F=[all|min|maj]::
 114 --pf=[all|min|maj]::
 115         Trace pagefaults. Optionally, you can specify whether you want minor,
 116         major or all pagefaults. Default value is maj.
 117
 118 --syscalls::
 119         Trace system calls. This options is enabled by default.
 120
 121 --event::
 122         Trace other events, see 'perf list' for a complete list.
 123
 124 --proc-map-timeout::
 125         When processing pre-existing threads /proc/XXX/mmap, it may take a long time,
 126         because the file may be huge. A time out is needed in such cases.
 127         This option sets the time out limit. The default value is 500 ms.
 128
 129 PAGEFAULTS
 130 ----------
 131
 132 When tracing pagefaults, the format of the trace is as follows:
 133
 134 <min|maj>fault [<ip.symbol>+<ip.offset>] => <addr.dso@addr.offset> (<map type><addr level>).
 135
 136 - min/maj indicates whether fault event is minor or major;
 137 - ip.symbol shows symbol for instruction pointer (the code that generated the
 138   fault); if no debug symbols available, perf trace will print raw IP;
 139 - addr.dso shows DSO for the faulted address;
 140 - map type is either 'd' for non-executable maps or 'x' for executable maps;
 141 - addr level is either 'k' for kernel dso or '.' for user dso.
 142
 143 For symbols resolution you may need to install debugging symbols.
 144
 145 Please be aware that duration is currently always 0 and doesn't reflect actual
 146 time it took for fault to be handled!
 147
 148 When --verbose specified, perf trace tries to print all available information
 149 for both IP and fault address in the form of dso@symbol+offset.
 150
 151 EXAMPLES
 152 --------
 153
 154 Trace only major pagefaults:
 155
 156  $ perf trace --no-syscalls -F
 157
 158 Trace syscalls, major and minor pagefaults:
 159
 160  $ perf trace -F all
 161
 162   1416.547 ( 0.000 ms): python/20235 majfault [CRYPTO_push_info_+0x0] => /lib/x86_64-linux-gnu/libcrypto.so.1.0.0@0x61be0 (x.)
 163
 164   As you can see, there was major pagefault in python process, from
 165   CRYPTO_push_info_ routine which faulted somewhere in libcrypto.so.
 166
 167 SEE ALSO
 168 --------
 169 linkperf:perf-record[1], linkperf:perf-script[1]