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perf trace: Make "--call-graph" affect just "raw_syscalls:sys_exit"

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We don't need the callchains at the syscall enter tracepoint, just when
finishing it at syscall exit, so reduce the overhead by asking for
callchains just at syscall exit.

Suggested-by: Milian Wolff <milian.wolff@kdab.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-fja1ods5vqpg42mdz09xcz3r@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo 2016-04-11 18:42:37 -03:00
parent 01e0d50c3f
commit fde54b7860
1 changed files with 21 additions and 1 deletions
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22
tools/perf/builtin-trace.c
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@ -2749,7 +2749,27 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
goto out_delete_evlist;
}
perf_evlist__config(evlist, &trace->opts, &callchain_param);
perf_evlist__config(evlist, &trace->opts, NULL);
if (trace->opts.callgraph_set && trace->syscalls.events.sys_exit) {
perf_evsel__config_callchain(trace->syscalls.events.sys_exit,
&trace->opts, &callchain_param);
/*
* Now we have evsels with different sample_ids, use
* PERF_SAMPLE_IDENTIFIER to map from sample to evsel
* from a fixed position in each ring buffer record.
*
* As of this the changeset introducing this comment, this
* isn't strictly needed, as the fields that can come before
* PERF_SAMPLE_ID are all used, but we'll probably disable
* some of those for things like copying the payload of
* pointer syscall arguments, and for vfs_getname we don't
* need PERF_SAMPLE_ADDR and PERF_SAMPLE_IP, so do this
* here as a warning we need to use PERF_SAMPLE_IDENTIFIER.
*/
perf_evlist__set_sample_bit(evlist, IDENTIFIER);
perf_evlist__reset_sample_bit(evlist, ID);
}
signal(SIGCHLD, sig_handler);
signal(SIGINT, sig_handler);