How to change input file name in perf sched record

I need to prove that when process is runnig and I remove the ELF file of this process number of free blocks and nodes in filesystem won't increase, and after I kill the process they increase. I also need to show latency in whole lifecycle of this process so I am using perf shed record ./Prog, but it makes a file and saving there results of recording and this destroys my first part of my task. When I try(logged as root) to use:

perf sched record -i /mnt/disk1 ./Prog &

I get

Workload failed: permission denied

Can someone tell me how to change the input file on file that is in other filesystem?

Solution

perf sched record has no option to change output file (-i is for input file not directory) according to man page http://man7.org/linux/man-pages/man1/perf-sched.1.html

  -i, --input=<file>
Input file name. (default: perf.data unless stdin is a fifo)

and to implementation: http://elixir.free-electrons.com/linux/v4.8/source/tools/perf/builtin-sched.c#L1896

tools/perf/builtin-sched.c
static int __cmd_record(int argc, const char **argv)
{
    unsigned int rec_argc, i, j;
    const char **rec_argv;
    const char * const record_args[] = {
        "record",
        "-a",
        "-R",
        "-m", "1024",
        "-c", "1",
        "-e", "sched:sched_switch",
        "-e", "sched:sched_stat_wait",
        "-e", "sched:sched_stat_sleep",
        "-e", "sched:sched_stat_iowait",
        "-e", "sched:sched_stat_runtime",
        "-e", "sched:sched_process_fork",
        "-e", "sched:sched_wakeup",
        "-e", "sched:sched_wakeup_new",
        "-e", "sched:sched_migrate_task",
    };
...
    return cmd_record(i, rec_argv, NULL);
}

int cmd_sched(int argc, const char **argv, const char *prefix __maybe_unused)
{
    const struct option sched_options[] = {
    OPT_STRING('i', "input", &input_name, "file",
            "input file name"),
    OPT_INCR('v', "verbose", &verbose,
            "be more verbose (show symbol address, etc)"),
    OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
            "dump raw trace in ASCII"),
    OPT_END()
    };
....    

static int perf_sched__read_events(struct perf_sched *sched)
{
...
    struct perf_data_file file = {
        .path = input_name,
        .mode = PERF_DATA_MODE_READ,
        .force = sched->force,
    };

But! The __cmd_record of builtin-sched.c calls default cmd_record of builtin_record.c which has -o option to specify output file: http://elixir.free-electrons.com/linux/v4.8/source/tools/perf/builtin-record.c#L1380

    OPT_STRING('o', "output", &record.file.path, "file",
            "output file name"),

So, you can change destination path for perf sched record by changing current dir, or you can try perf sched record -o /mnt/disk1/perf.data ./Prog &. Don't use directory name as argument of -i (input for report) / -o (output for record) perf options.