This adds an option '-m/--buffer-size' to allow us set the size of per-cpu tracing buffer.
Signed-off-by: Changbin Du <[email protected]> --- tools/perf/Documentation/perf-ftrace.txt | 4 ++++ tools/perf/builtin-ftrace.c | 22 ++++++++++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt index fd1776deebd7..a18d640e90bb 100644 --- a/tools/perf/Documentation/perf-ftrace.txt +++ b/tools/perf/Documentation/perf-ftrace.txt @@ -60,6 +60,10 @@ OPTIONS Ranges of CPUs are specified with -: 0-2. Default is to trace on all online CPUs. +-m:: +--buffer-size:: + Set the size of per-cpu tracing buffer in KB. + -T:: --trace-funcs=:: Only trace functions given by the argument. Multiple functions diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 003efa756322..e45496012611 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -39,6 +39,7 @@ struct perf_ftrace { struct list_head nograph_funcs; int graph_depth; unsigned initial_delay; + unsigned buffer_size_kb; }; struct filter_entry { @@ -321,6 +322,20 @@ static int set_tracing_depth(struct perf_ftrace *ftrace) return 0; } +static int set_tracing_buffer_size_kb(struct perf_ftrace *ftrace) +{ + int ret; + + if (ftrace->buffer_size_kb == 0) + return 0; + + ret = write_tracing_file_int("buffer_size_kb", ftrace->buffer_size_kb); + if (ret < 0) + return ret; + + return 0; +} + static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) { char *trace_file; @@ -385,6 +400,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) goto out_reset; } + if (set_tracing_buffer_size_kb(ftrace) < 0) { + pr_err("failed to set tracing per-cpu buffer size\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; @@ -555,6 +575,8 @@ int cmd_ftrace(int argc, const char **argv) "Max depth for function graph tracer"), OPT_UINTEGER('d', "delay", &ftrace.initial_delay, "ms to wait before starting tracing after program start"), + OPT_UINTEGER('m', "buffer-size", &ftrace.buffer_size_kb, + "size of per cpu buffer in kb"), OPT_END() }; -- 2.25.1
