From b1d84af6f58022a0d75f5745367624549cd0bfbf Mon Sep 17 00:00:00 2001 From: Changbin Du Date: Sat, 8 Aug 2020 10:31:31 +0800 Subject: [PATCH] perf ftrace: Add support for tracing option 'func_stack_trace' This adds support to display call trace for function tracer. To do this, just specify a '--func-opts call-graph' option. Example: $ sudo perf ftrace -T vfs_read --func-opts call-graph iio-sensor-prox-855 [003] 6168.369657: vfs_read <-ksys_read iio-sensor-prox-855 [003] 6168.369677: => vfs_read => ksys_read => __x64_sys_read => do_syscall_64 => entry_SYSCALL_64_after_hwframe ... Signed-off-by: Changbin Du Acked-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Steven Rostedt (VMware) Link: http://lore.kernel.org/lkml/20200808023141.14227-9-changbin.du@gmail.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-ftrace.txt | 4 +++ tools/perf/builtin-ftrace.c | 42 ++++++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+) diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt index c46d0a0..8f08ad0 100644 --- a/tools/perf/Documentation/perf-ftrace.txt +++ b/tools/perf/Documentation/perf-ftrace.txt @@ -76,6 +76,10 @@ OPTIONS specify multiple functions (or glob patterns). It will be passed to 'set_ftrace_notrace' in tracefs. +--func-opts:: + List of options allowed to set: + call-graph - Display kernel stack trace for function tracer. + -G:: --graph-funcs=:: Select function_graph tracer and set graph filter on the given diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 07b81d0..469b897 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -27,6 +27,7 @@ #include "util/cap.h" #include "util/config.h" #include "util/units.h" +#include "util/parse-sublevel-options.h" #define DEFAULT_TRACER "function_graph" @@ -42,6 +43,7 @@ struct perf_ftrace { int graph_depth; unsigned long percpu_buffer_size; bool inherit; + int func_stack_trace; }; struct filter_entry { @@ -202,6 +204,7 @@ static void reset_tracing_filters(void); static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused) { write_tracing_option_file("function-fork", "0"); + write_tracing_option_file("func_stack_trace", "0"); } static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused) @@ -278,6 +281,17 @@ static int set_tracing_cpu(struct perf_ftrace *ftrace) return set_tracing_cpumask(cpumap); } +static int set_tracing_func_stack_trace(struct perf_ftrace *ftrace) +{ + if (!ftrace->func_stack_trace) + return 0; + + if (write_tracing_option_file("func_stack_trace", "1") < 0) + return -1; + + return 0; +} + static int reset_tracing_cpu(void) { struct perf_cpu_map *cpumap = perf_cpu_map__new(NULL); @@ -426,6 +440,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) goto out_reset; } + if (set_tracing_func_stack_trace(ftrace) < 0) { + pr_err("failed to set tracing option func_stack_trace\n"); + goto out_reset; + } + if (set_tracing_filters(ftrace) < 0) { pr_err("failed to set tracing filters\n"); goto out_reset; @@ -598,6 +617,26 @@ static int parse_buffer_size(const struct option *opt, return -1; } +static int parse_func_tracer_opts(const struct option *opt, + const char *str, int unset) +{ + int ret; + struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value; + struct sublevel_option func_tracer_opts[] = { + { .name = "call-graph", .value_ptr = &ftrace->func_stack_trace }, + { .name = NULL, } + }; + + if (unset) + return 0; + + ret = perf_parse_sublevel_options(str, func_tracer_opts); + if (ret) + return ret; + + return 0; +} + static void select_tracer(struct perf_ftrace *ftrace) { bool graph = !list_empty(&ftrace->graph_funcs) || @@ -645,6 +684,9 @@ int cmd_ftrace(int argc, const char **argv) parse_filter_func), OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func", "do not trace given functions", parse_filter_func), + OPT_CALLBACK(0, "func-opts", &ftrace, "options", + "function tracer options, available options: call-graph", + parse_func_tracer_opts), OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func", "trace given functions using function_graph tracer", parse_filter_func), -- 2.7.4