From d6d81bfe429ee7e3e59388d16741b354a2484f0f Mon Sep 17 00:00:00 2001 From: Changbin Du Date: Sat, 8 Aug 2020 10:31:25 +0800 Subject: [PATCH] perf ftrace: Add option '-F/--funcs' to list available functions This adds an option '-F/--funcs' to list all available functions to trace, which is read from tracing file 'available_filter_functions'. $ sudo ./perf ftrace -F | head trace_initcall_finish_cb initcall_blacklisted do_one_initcall do_one_initcall trace_initcall_start_cb run_init_process try_to_run_init_process match_dev_by_label match_dev_by_uuid rootfs_init_fs_context $ Committer notes: This is the same command line option and for the same purpose as in 'perf probe'. Signed-off-by: Changbin Du Tested-by: Arnaldo Carvalho de Melo Acked-by: Namhyung Kim Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Steven Rostedt (VMware) Link: http://lore.kernel.org/lkml/20200808023141.14227-3-changbin.du@gmail.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-ftrace.txt | 4 +++ tools/perf/builtin-ftrace.c | 46 ++++++++++++++++++++++++ 2 files changed, 50 insertions(+) diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt index 821d4d334a09..4f5628445a63 100644 --- a/tools/perf/Documentation/perf-ftrace.txt +++ b/tools/perf/Documentation/perf-ftrace.txt @@ -31,6 +31,10 @@ OPTIONS --verbose=:: Verbosity level. +-F:: +--funcs:: + List all available functions to trace. + -p:: --pid=:: Trace on existing process id (comma separated list). diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 048a11192b59..1ebf71ecc1a8 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -33,6 +33,7 @@ struct perf_ftrace { struct evlist *evlist; struct target target; const char *tracer; + bool list_avail_functions; struct list_head filters; struct list_head notrace; struct list_head graph_funcs; @@ -128,6 +129,46 @@ static int append_tracing_file(const char *name, const char *val) return __write_tracing_file(name, val, true); } +static int read_tracing_file_to_stdout(const char *name) +{ + char buf[4096]; + char *file; + int fd; + int ret = -1; + + file = get_tracing_file(name); + if (!file) { + pr_debug("cannot get tracing file: %s\n", name); + return -1; + } + + fd = open(file, O_RDONLY); + if (fd < 0) { + pr_debug("cannot open tracing file: %s: %s\n", + name, str_error_r(errno, buf, sizeof(buf))); + goto out; + } + + /* read contents to stdout */ + while (true) { + int n = read(fd, buf, sizeof(buf)); + if (n == 0) + break; + else if (n < 0) + goto out_close; + + if (fwrite(buf, n, 1, stdout) != 1) + goto out_close; + } + ret = 0; + +out_close: + close(fd); +out: + put_tracing_file(file); + return ret; +} + static int reset_tracing_cpu(void); static void reset_tracing_filters(void); @@ -302,6 +343,9 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) signal(SIGCHLD, sig_handler); signal(SIGPIPE, sig_handler); + if (ftrace->list_avail_functions) + return read_tracing_file_to_stdout("available_filter_functions"); + if (reset_tracing_files(ftrace) < 0) { pr_err("failed to reset ftrace\n"); goto out; @@ -487,6 +531,8 @@ int cmd_ftrace(int argc, const char **argv) const struct option ftrace_options[] = { OPT_STRING('t', "tracer", &ftrace.tracer, "tracer", "tracer to use: function_graph(default) or function"), + OPT_BOOLEAN('F', "funcs", &ftrace.list_avail_functions, + "Show available functions to filter"), OPT_STRING('p', "pid", &ftrace.target.pid, "pid", "trace on existing process id"), OPT_INCR('v', "verbose", &verbose, -- 2.20.1