Hi Arnaldo,
On 02/22/2019 10:53 PM, Arnaldo Carvalho de Melo wrote:
> 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.
Thanks for your advice, I will modify the patch and send a v3.
Thanks,
Regards,
Jiwei
>
>
> - 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
>
