Messages in this thread Patch in this message | | | From | Changbin Du <> | Subject | [PATCH v2 02/15] perf ftrace: add option '-F/--funcs' to list available functions | Date | Sat, 27 Jun 2020 21:36:41 +0800 |
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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
Signed-off-by: Changbin Du <changbin.du@gmail.com>
--- v2: option name '-l/--list-functions' -> '-F/--funcs' --- tools/perf/Documentation/perf-ftrace.txt | 4 +++ tools/perf/builtin-ftrace.c | 43 ++++++++++++++++++++++++ 2 files changed, 47 insertions(+)
diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt index 952e46669168..d79560dea19f 100644 --- a/tools/perf/Documentation/perf-ftrace.txt +++ b/tools/perf/Documentation/perf-ftrace.txt @@ -30,6 +30,10 @@ 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 c5718503eded..e793118e83a9 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -32,6 +32,7 @@ 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; @@ -127,6 +128,43 @@ 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) + 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); @@ -301,6 +339,9 @@ 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; @@ -470,6 +511,8 @@ int cmd_ftrace(int argc, const char **argv) const struct option ftrace_options[] = { OPT_STRING('t', "tracer", &ftrace.tracer, "tracer", "tracer to use: function or function_graph (This option is deprecated)"), + 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, -- 2.25.1
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