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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-04-11 15:49:11 -0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-04-11 22:18:19 -0300 |
| commit | 44621819ddc9d5d0bfd0b0616c6cf33c94189b67 (patch) | |
| tree | ffd8713f48d2e835debbea10b2809adc8e395c67 /tools/perf/builtin-trace.c | |
| parent | ea4539652eccc87b14fbcbc90467ebcb87f02ddb (diff) | |
| download | lwn-44621819ddc9d5d0bfd0b0616c6cf33c94189b67.tar.gz lwn-44621819ddc9d5d0bfd0b0616c6cf33c94189b67.zip | |
perf trace: Exclude the kernel part of the callchain leading to a syscall
The kernel parts are not that useful:
# trace -m 512 -e nanosleep --call dwarf usleep 1
0.065 ( 0.065 ms): usleep/18732 nanosleep(rqtp: 0x7ffc4ee4e200) = 0
syscall_slow_exit_work ([kernel.kallsyms])
do_syscall_64 ([kernel.kallsyms])
return_from_SYSCALL_64 ([kernel.kallsyms])
__nanosleep (/usr/lib64/libc-2.22.so)
usleep (/usr/lib64/libc-2.22.so)
main (/usr/bin/usleep)
__libc_start_main (/usr/lib64/libc-2.22.so)
_start (/usr/bin/usleep)
#
So lets just use perf_event_attr.exclude_callchain_kernel to avoid
collecting it in the ring buffer:
# trace -m 512 -e nanosleep --call dwarf usleep 1
0.063 ( 0.063 ms): usleep/19212 nanosleep(rqtp: 0x7ffc3df10fb0) = 0
__nanosleep (/usr/lib64/libc-2.22.so)
usleep (/usr/lib64/libc-2.22.so)
main (/usr/bin/usleep)
__libc_start_main (/usr/lib64/libc-2.22.so)
_start (/usr/bin/usleep)
#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-qctu3gqhpim0dfbcp9d86c91@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/builtin-trace.c')
| -rw-r--r-- | tools/perf/builtin-trace.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 63a3cc9b717c..cfa5ce8fdb7b 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -159,6 +159,7 @@ struct trace { bool show_comm; bool show_tool_stats; bool trace_syscalls; + bool kernel_syscallchains; bool force; bool vfs_getname; int trace_pgfaults; @@ -2661,6 +2662,15 @@ static int trace__add_syscall_newtp(struct trace *trace) perf_evlist__add(evlist, sys_enter); perf_evlist__add(evlist, sys_exit); + if (trace->opts.callgraph_set && !trace->kernel_syscallchains) { + /* + * We're interested only in the user space callchain + * leading to the syscall, allow overriding that for + * debugging reasons using --kernel_syscall_callchains + */ + sys_exit->attr.exclude_callchain_kernel = 1; + } + trace->syscalls.events.sys_enter = sys_enter; trace->syscalls.events.sys_exit = sys_exit; @@ -3221,6 +3231,7 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused) .output = stderr, .show_comm = true, .trace_syscalls = true, + .kernel_syscallchains = false, }; const char *output_name = NULL; const char *ev_qualifier_str = NULL; @@ -3269,6 +3280,8 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused) OPT_CALLBACK(0, "call-graph", &trace.opts, "record_mode[,record_size]", record_callchain_help, &record_parse_callchain_opt), + OPT_BOOLEAN(0, "kernel-syscall-graph", &trace.kernel_syscallchains, + "Show the kernel callchains on the syscall exit path"), OPT_UINTEGER(0, "proc-map-timeout", &trace.opts.proc_map_timeout, "per thread proc mmap processing timeout in ms"), OPT_END() |