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Diffstat (limited to 'tools/perf/Documentation/perf-trace.txt')
| -rw-r--r-- | tools/perf/Documentation/perf-trace.txt | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt index fae38d9a44a4..02aac831bdd9 100644 --- a/tools/perf/Documentation/perf-trace.txt +++ b/tools/perf/Documentation/perf-trace.txt @@ -107,6 +107,52 @@ the thread executes on the designated CPUs. Default is to monitor all CPUs. Show tool stats such as number of times fd->pathname was discovered thru hooking the open syscall return + vfs_getname or via reading /proc/pid/fd, etc. +-F=[all|min|maj]:: +--pf=[all|min|maj]:: + Trace pagefaults. Optionally, you can specify whether you want minor, + major or all pagefaults. Default value is maj. + +--syscalls:: + Trace system calls. This options is enabled by default. + +PAGEFAULTS +---------- + +When tracing pagefaults, the format of the trace is as follows: + +<min|maj>fault [<ip.symbol>+<ip.offset>] => <addr.dso@addr.offset> (<map type><addr level>). + +- min/maj indicates whether fault event is minor or major; +- ip.symbol shows symbol for instruction pointer (the code that generated the + fault); if no debug symbols available, perf trace will print raw IP; +- addr.dso shows DSO for the faulted address; +- map type is either 'd' for non-executable maps or 'x' for executable maps; +- addr level is either 'k' for kernel dso or '.' for user dso. + +For symbols resolution you may need to install debugging symbols. + +Please be aware that duration is currently always 0 and doesn't reflect actual +time it took for fault to be handled! + +When --verbose specified, perf trace tries to print all available information +for both IP and fault address in the form of dso@symbol+offset. + +EXAMPLES +-------- + +Trace only major pagefaults: + + $ perf trace --no-syscalls -F + +Trace syscalls, major and minor pagefaults: + + $ perf trace -F all + + 1416.547 ( 0.000 ms): python/20235 majfault [CRYPTO_push_info_+0x0] => /lib/x86_64-linux-gnu/libcrypto.so.1.0.0@0x61be0 (x.) + + As you can see, there was major pagefault in python process, from + CRYPTO_push_info_ routine which faulted somewhere in libcrypto.so. + SEE ALSO -------- linkperf:perf-record[1], linkperf:perf-script[1] |