From: Arnaldo Carvalho de Melo <[email protected]> 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 <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Milian Wolff <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Wang Nan <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- 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 4e8baa75a32e..146c6db21cbf 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 6a64cb1344c7..19f5100acc1d 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; -- 2.5.5
