Commit-ID: 056149932602ef905f1e26fc4fe242ef0533a597
Gitweb: http://git.kernel.org/tip/056149932602ef905f1e26fc4fe242ef0533a597
Author: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Fri, 15 Apr 2016 16:41:19 -0300
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Fri, 15 Apr 2016 16:41:19 -0300
perf trace: Make --(min,max}-stack imply "--call-graph dwarf"
If one uses:
# perf trace --min-stack 16
Then it implicitly means that callgraphs should be enabled, and the best
option in terms of widespread availability is "dwarf".
Further work needed to choose a better alternative, LBR, in capable
systems.
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Milian Wolff <milian.wolff@xxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-xtjmnpkyk42npekxz3kynzmx@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Documentation/perf-trace.txt | 6 ++++++
tools/perf/builtin-trace.c | 13 ++++++++++++-
2 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt
index 4e8baa7..146c6db 100644
--- a/tools/perf/Documentation/perf-trace.txt
+++ b/tools/perf/Documentation/perf-trace.txt
@@ -136,12 +136,18 @@ the thread executes on the designated CPUs. Default is to monitor all CPUs.
not limiting, the overhead of callchains needs to be set via the
knobs in --call-graph dwarf.
+ Implies '--call-graph dwarf' when --call-graph not present on the
+ command line, on systems where DWARF unwinding was built in.
+
Default: 127
--min-stack::
Set the stack depth limit when parsing the callchain, anything
below the specified depth will be ignored. Disabled by default.
+ Implies '--call-graph dwarf' when --call-graph not present on the
+ command line, on systems where DWARF unwinding was built in.
+
--proc-map-timeout::
When processing pre-existing threads /proc/XXX/mmap, it may take a long time,
because the file may be huge. A time out is needed in such cases.
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 6a64cb1..19f5100 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -3047,7 +3047,7 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
.show_comm = true,
.trace_syscalls = true,
.kernel_syscallchains = false,
- .max_stack = PERF_MAX_STACK_DEPTH,
+ .max_stack = UINT_MAX,
};
const char *output_name = NULL;
const char *ev_qualifier_str = NULL;
@@ -3109,6 +3109,7 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
"per thread proc mmap processing timeout in ms"),
OPT_END()
};
+ bool max_stack_user_set = true;
const char * const trace_subcommands[] = { "record", NULL };
int err;
char bf[BUFSIZ];
@@ -3142,6 +3143,16 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
trace.opts.sample_time = true;
}
+ if (trace.max_stack == UINT_MAX) {
+ trace.max_stack = PERF_MAX_STACK_DEPTH;
+ max_stack_user_set = false;
+ }
+
+#ifdef HAVE_DWARF_UNWIND_SUPPORT
+ if ((trace.min_stack || max_stack_user_set) && !trace.opts.callgraph_set)
+ record_opts__parse_callchain(&trace.opts, &callchain_param, "dwarf", false);
+#endif
+
if (trace.opts.callgraph_set)
symbol_conf.use_callchain = true;
--
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