The perf ftrace fails to reset tracer after finish the recording like below:
$ sudo perf ftrace -v hello write 'nop' to tracing/current_tracer failed: Device or resource busy ... This is because the trace_pipe file is open in pager process. Move the pager setup before opening the file. Cc: Steven Rostedt <[email protected]> Cc: Frederic Weisbecker <[email protected]> Fixes: 583359646fde ("perf ftrace: Use pager for displaying result") Signed-off-by: Namhyung Kim <[email protected]> --- tools/perf/builtin-ftrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 966a94fa8200..982b98ee639e 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -231,6 +231,8 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) goto out_reset; } + setup_pager(); + trace_file = get_tracing_file("trace_pipe"); if (!trace_file) { pr_err("failed to open trace_pipe\n"); @@ -254,8 +256,6 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) goto out_close_fd; } - setup_pager(); - perf_evlist__start_workload(ftrace->evlist); while (!done) { -- 2.13.0
