From 1096c35aa821cc4789a64232a0e210bb87a0e5e8 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Sun, 18 Jun 2017 23:23:02 +0900 Subject: [PATCH] perf ftrace: Add -D option for depth filter The -D/--graph-depth option is to set max graph depth. The following example traces max 2-depth of page fault handler. $ sudo perf ftrace -G __do_page_fault -D 2 -- hello ... 0) | __do_page_fault() { 0) 0.063 us | down_read_trylock(); 0) 0.251 us | find_vma(); 0) 5.374 us | handle_mm_fault(); 0) 0.054 us | up_read(); 0) 7.463 us | } ... Signed-off-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Peter Zijlstra Cc: Steven Rostedt Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170618142302.25390-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-ftrace.txt | 3 +++ tools/perf/builtin-ftrace.c | 31 ++++++++++++++++++++++++ 2 files changed, 34 insertions(+) diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt index 78d6126ca485..721a447f046e 100644 --- a/tools/perf/Documentation/perf-ftrace.txt +++ b/tools/perf/Documentation/perf-ftrace.txt @@ -78,6 +78,9 @@ OPTIONS This can be used more than once to specify multiple functions. It will be passed to 'set_graph_notrace' in tracefs. +-D:: +--graph-depth=:: + Set max depth for function graph tracer to follow SEE ALSO -------- diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 3285375ce3c2..dd26c62c9893 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -35,6 +35,7 @@ struct perf_ftrace { struct list_head notrace; struct list_head graph_funcs; struct list_head nograph_funcs; + int graph_depth; }; struct filter_entry { @@ -129,6 +130,9 @@ static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused) if (reset_tracing_cpu() < 0) return -1; + if (write_tracing_file("max_graph_depth", "0") < 0) + return -1; + reset_tracing_filters(); return 0; } @@ -237,6 +241,26 @@ static void reset_tracing_filters(void) write_tracing_file("set_graph_notrace", " "); } +static int set_tracing_depth(struct perf_ftrace *ftrace) +{ + char buf[16]; + + if (ftrace->graph_depth == 0) + return 0; + + if (ftrace->graph_depth < 0) { + pr_err("invalid graph depth: %d\n", ftrace->graph_depth); + return -1; + } + + snprintf(buf, sizeof(buf), "%d", ftrace->graph_depth); + + if (write_tracing_file("max_graph_depth", buf) < 0) + return -1; + + return 0; +} + static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) { char *trace_file; @@ -284,6 +308,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) goto out_reset; } + if (set_tracing_depth(ftrace) < 0) { + pr_err("failed to set graph depth\n"); + goto out_reset; + } + if (write_tracing_file("current_tracer", ftrace->tracer) < 0) { pr_err("failed to set current_tracer to %s\n", ftrace->tracer); goto out_reset; @@ -425,6 +454,8 @@ int cmd_ftrace(int argc, const char **argv) "Set graph filter on given functions", parse_filter_func), OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func", "Set nograph filter on given functions", parse_filter_func), + OPT_INTEGER('D', "graph-depth", &ftrace.graph_depth, + "Max depth for function graph tracer"), OPT_END() }; -- 2.20.1