1perf-trace(1) 2============= 3 4NAME 5---- 6perf-trace - strace inspired tool 7 8SYNOPSIS 9-------- 10[verse] 11'perf trace' 12'perf trace record' 13 14DESCRIPTION 15----------- 16This command will show the events associated with the target, initially 17syscalls, but other system events like pagefaults, task lifetime events, 18scheduling events, etc. 19 20This is a live mode tool in addition to working with perf.data files like 21the other perf tools. Files can be generated using the 'perf record' command 22but the session needs to include the raw_syscalls events (-e 'raw_syscalls:*'). 23Alternatively, 'perf trace record' can be used as a shortcut to 24automatically include the raw_syscalls events when writing events to a file. 25 26The following options apply to perf trace; options to perf trace record are 27found in the perf record man page. 28 29OPTIONS 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--no-inherit:: 66 Child tasks do not inherit counters. 67 68-m:: 69--mmap-pages=:: 70 Number of mmap data pages (must be a power of two) or size 71 specification with appended unit character - B/K/M/G. The 72 size is rounded up to have nearest pages power of two value. 73 74-C:: 75--cpu:: 76Collect samples only on the list of CPUs provided. Multiple CPUs can be provided as a 77comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2. 78In per-thread mode with inheritance mode on (default), Events are captured only when 79the thread executes on the designated CPUs. Default is to monitor all CPUs. 80 81--duration: 82 Show only events that had a duration greater than N.M ms. 83 84--sched: 85 Accrue thread runtime and provide a summary at the end of the session. 86 87-i 88--input 89 Process events from a given perf data file. 90 91-T 92--time 93 Print full timestamp rather time relative to first sample. 94 95--comm:: 96 Show process COMM right beside its ID, on by default, disable with --no-comm. 97 98-s:: 99--summary:: 100 Show only a summary of syscalls by thread with min, max, and average times 101 (in msec) and relative stddev. 102 103-S:: 104--with-summary:: 105 Show all syscalls followed by a summary by thread with min, max, and 106 average times (in msec) and relative stddev. 107 108--tool_stats:: 109 Show tool stats such as number of times fd->pathname was discovered thru 110 hooking the open syscall return + vfs_getname or via reading /proc/pid/fd, etc. 111 112-F=[all|min|maj]:: 113--pf=[all|min|maj]:: 114 Trace pagefaults. Optionally, you can specify whether you want minor, 115 major or all pagefaults. Default value is maj. 116 117--syscalls:: 118 Trace system calls. This options is enabled by default. 119 120--event:: 121 Trace other events, see 'perf list' for a complete list. 122 123--proc-map-timeout:: 124 When processing pre-existing threads /proc/XXX/mmap, it may take a long time, 125 because the file may be huge. A time out is needed in such cases. 126 This option sets the time out limit. The default value is 500 ms. 127 128PAGEFAULTS 129---------- 130 131When tracing pagefaults, the format of the trace is as follows: 132 133<min|maj>fault [<ip.symbol>+<ip.offset>] => <addr.dso@addr.offset> (<map type><addr level>). 134 135- min/maj indicates whether fault event is minor or major; 136- ip.symbol shows symbol for instruction pointer (the code that generated the 137 fault); if no debug symbols available, perf trace will print raw IP; 138- addr.dso shows DSO for the faulted address; 139- map type is either 'd' for non-executable maps or 'x' for executable maps; 140- addr level is either 'k' for kernel dso or '.' for user dso. 141 142For symbols resolution you may need to install debugging symbols. 143 144Please be aware that duration is currently always 0 and doesn't reflect actual 145time it took for fault to be handled! 146 147When --verbose specified, perf trace tries to print all available information 148for both IP and fault address in the form of dso@symbol+offset. 149 150EXAMPLES 151-------- 152 153Trace only major pagefaults: 154 155 $ perf trace --no-syscalls -F 156 157Trace syscalls, major and minor pagefaults: 158 159 $ perf trace -F all 160 161 1416.547 ( 0.000 ms): python/20235 majfault [CRYPTO_push_info_+0x0] => /lib/x86_64-linux-gnu/libcrypto.so.1.0.0@0x61be0 (x.) 162 163 As you can see, there was major pagefault in python process, from 164 CRYPTO_push_info_ routine which faulted somewhere in libcrypto.so. 165 166SEE ALSO 167-------- 168linkperf:perf-record[1], linkperf:perf-script[1] 169