Em Fri, Feb 22, 2019 at 03:19:04PM +0800, Jiwei Sun escreveu:
> The patch adds a new option to limit the output file size, then based
> on it, we can create a wrapper of the perf command that uses the option
> to avoid exhausting the disk space by the unconscious user.
>
> Signed-off-by: Jiwei Sun <jiwei....@windriver.com>
> ---
> v2 changes:
Please do a v3 adding this new option to
tools/perf/Documentation/perf-record.txt
Please also rename it to --max-size-output, because then we coudl use:
perf record --max-size-output
or:
perf record --max-size
or even:
perf record --max saving typing :-)
Also please show it in use, i.e. the output of it working.
- Arnaldo
> - make patch based on latest Arnaldo's perf/core,
> - display warning message when reached the limit.
> ---
> tools/perf/builtin-record.c | 42 +++++++++++++++++++++++++++++++++++++
> 1 file changed, 42 insertions(+)
>
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 6c3719ac901d..dc3648c0816d 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -83,6 +83,7 @@ struct record {
> struct switch_output switch_output;
> unsigned long long samples;
> cpu_set_t affinity_mask;
> + unsigned long output_max_size; /* = 0: unlimited */
> };
>
> static volatile int auxtrace_record__snapshot_started;
> @@ -112,6 +113,12 @@ static bool switch_output_time(struct record *rec)
> trigger_is_ready(&switch_output_trigger);
> }
>
> +static bool record__output_max_size_exceeded(struct record *rec)
> +{
> + return (rec->output_max_size &&
> + rec->bytes_written >= rec->output_max_size);
> +}
> +
> static int record__write(struct record *rec, struct perf_mmap *map
> __maybe_unused,
> void *bf, size_t size)
> {
> @@ -124,6 +131,12 @@ static int record__write(struct record *rec, struct
> perf_mmap *map __maybe_unuse
>
> rec->bytes_written += size;
>
> + if (record__output_max_size_exceeded(rec)) {
> + pr_warning("WARNING: The perf data has already reached "
> + "the limit, stop recording!\n");
> + raise(SIGTERM);
> + }
> +
> if (switch_output_size(rec))
> trigger_hit(&switch_output_trigger);
>
> @@ -1671,6 +1684,33 @@ static int record__parse_affinity(const struct option
> *opt, const char *str, int
> return 0;
> }
>
> +static int parse_output_max_size(const struct option *opt,
> + const char *str, int unset)
> +{
> + unsigned long *s = (unsigned long *)opt->value;
> + static struct parse_tag tags_size[] = {
> + { .tag = 'B', .mult = 1 },
> + { .tag = 'K', .mult = 1 << 10 },
> + { .tag = 'M', .mult = 1 << 20 },
> + { .tag = 'G', .mult = 1 << 30 },
> + { .tag = 0 },
> + };
> + unsigned long val;
> +
> + if (unset) {
> + *s = 0;
> + return 0;
> + }
> +
> + val = parse_tag_value(str, tags_size);
> + if (val != (unsigned long) -1) {
> + *s = val;
> + return 0;
> + }
> +
> + return -1;
> +}
> +
> static int record__parse_mmap_pages(const struct option *opt,
> const char *str,
> int unset __maybe_unused)
> @@ -1982,6 +2022,8 @@ static struct option __record_options[] = {
> OPT_CALLBACK(0, "affinity", &record.opts, "node|cpu",
> "Set affinity mask of trace reading thread to NUMA node
> cpu mask or cpu of processed mmap buffer",
> record__parse_affinity),
> + OPT_CALLBACK(0, "output-max-size", &record.output_max_size,
> + "size", "Output file maximum size", parse_output_max_size),
> OPT_END()
> };
>
> --
> 2.20.1
--
- Arnaldo
