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-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:: 77Collect samples only on the list of CPUs provided. Multiple CPUs can be provided as a 78comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2. 79In per-thread mode with inheritance mode on (default), Events are captured only when 80the 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 129PAGEFAULTS 130---------- 131 132When 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 143For symbols resolution you may need to install debugging symbols. 144 145Please be aware that duration is currently always 0 and doesn't reflect actual 146time it took for fault to be handled! 147 148When --verbose specified, perf trace tries to print all available information 149for both IP and fault address in the form of dso@symbol+offset. 150 151EXAMPLES 152-------- 153 154Trace only major pagefaults: 155 156 $ perf trace --no-syscalls -F 157 158Trace 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 167SEE ALSO 168-------- 169linkperf:perf-record[1], linkperf:perf-script[1] 170