Re: [PATCH 09/44] perf session: Add instruction tracing options

From: Arnaldo Carvalho de Melo
Date: Tue Apr 21 2015 - 10:50:50 EST


Em Thu, Apr 09, 2015 at 06:53:49PM +0300, Adrian Hunter escreveu:

> It is assumed that AUX area decoding will synthesize events for
> consumption by other tools. At this time, the main use of AUX area
> tracing will be to capture instruction trace (aka processor trace)
> data. The nature of instruction tracing suggests the initial
> inclusion of options for "instructions" and "branches" events, but
> more could be added as needed.

> +++ b/tools/perf/util/auxtrace.c
> @@ -37,6 +37,7 @@
>
> #include "event.h"
> #include "debug.h"
> +#include "parse-options.h"
>
> int auxtrace_mmap__mmap(struct auxtrace_mmap *mm,
> struct auxtrace_mmap_params *mp,
> @@ -200,6 +201,136 @@ out_free:
> return err;
> }
>
> +#define PERF_ITRACE_DEFAULT_PERIOD_TYPE PERF_ITRACE_PERIOD_NANOSECS
> +#define PERF_ITRACE_DEFAULT_PERIOD 100000
> +#define PERF_ITRACE_DEFAULT_CALLCHAIN_SZ 16
> +#define PERF_ITRACE_MAX_CALLCHAIN_SZ 1024
> +
> +void itrace_synth_opts__set_default(struct itrace_synth_opts *synth_opts)
> +{
> + synth_opts->instructions = true;
> + synth_opts->branches = true;
> + synth_opts->errors = true;
> + synth_opts->period_type = PERF_ITRACE_DEFAULT_PERIOD_TYPE;
> + synth_opts->period = PERF_ITRACE_DEFAULT_PERIOD;
> + synth_opts->callchain_sz = PERF_ITRACE_DEFAULT_CALLCHAIN_SZ;
> +}
> +
> +int itrace_parse_synth_opts(const struct option *opt, const char *str,
> + int unset)
> +{
> + struct itrace_synth_opts *synth_opts = opt->value;
> + const char *p;
> + char *endptr;
> +
> + synth_opts->set = true;
> +
> + if (unset) {
> + synth_opts->dont_decode = true;
> + return 0;
> + }
> +
> + if (!str) {
> + itrace_synth_opts__set_default(synth_opts);
> + return 0;
> + }
> +
> + for (p = str; *p;) {
> + switch (*p++) {
> + case 'i':
> + synth_opts->instructions = true;

Is this documented anywhere? I.e. examples for setting up this synth
ops?

> + while (*p == ' ' || *p == ',')
> + p += 1;
> + if (isdigit(*p)) {
> + synth_opts->period = strtoull(p, &endptr, 10);
> + p = endptr;
> + while (*p == ' ' || *p == ',')
> + p += 1;
> + switch (*p++) {
> + case 'i':
> + synth_opts->period_type =
> + PERF_ITRACE_PERIOD_INSTRUCTIONS;
> + break;
> + case 't':
> + synth_opts->period_type =
> + PERF_ITRACE_PERIOD_TICKS;
> + break;
> + case 'm':
> + synth_opts->period *= 1000;
> + /* Fall through */
> + case 'u':
> + synth_opts->period *= 1000;
> + /* Fall through */
> + case 'n':
> + if (*p++ != 's')
> + goto out_err;
> + synth_opts->period_type =
> + PERF_ITRACE_PERIOD_NANOSECS;
> + break;
> + case '\0':
> + goto out;
> + default:
> + goto out_err;
> + }
> + }
> + break;
> + case 'b':
> + synth_opts->branches = true;
> + break;
> + case 'e':
> + synth_opts->errors = true;
> + break;
> + case 'd':
> + synth_opts->log = true;
> + break;
> + case 'c':
> + synth_opts->branches = true;
> + synth_opts->calls = true;
> + break;
> + case 'r':
> + synth_opts->branches = true;
> + synth_opts->returns = true;
> + break;
> + case 'g':
> + synth_opts->instructions = true;
> + synth_opts->callchain = true;
> + synth_opts->callchain_sz =
> + PERF_ITRACE_DEFAULT_CALLCHAIN_SZ;
> + while (*p == ' ' || *p == ',')
> + p += 1;
> + if (isdigit(*p)) {
> + unsigned int val;
> +
> + val = strtoul(p, &endptr, 10);
> + p = endptr;
> + if (!val || val > PERF_ITRACE_MAX_CALLCHAIN_SZ)
> + goto out_err;
> + synth_opts->callchain_sz = val;
> + }
> + break;
> + case ' ':
> + case ',':
> + break;
> + default:
> + goto out_err;
> + }
> + }
> +out:
> + if (synth_opts->instructions) {
> + if (!synth_opts->period_type)
> + synth_opts->period_type =
> + PERF_ITRACE_DEFAULT_PERIOD_TYPE;
> + if (!synth_opts->period)
> + synth_opts->period = PERF_ITRACE_DEFAULT_PERIOD;
> + }
> +
> + return 0;
> +
> +out_err:
> + pr_err("Bad Instruction Tracing options '%s'\n", str);
> + return -EINVAL;
> +}
> +
> int auxtrace_mmap__read(struct auxtrace_mmap *mm, struct auxtrace_record *itr,
> struct perf_tool *tool, process_auxtrace_t fn)
> {
> diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h
> index 199fc27..6355315 100644
> --- a/tools/perf/util/auxtrace.h
> +++ b/tools/perf/util/auxtrace.h
> @@ -29,9 +29,49 @@ union perf_event;
> struct perf_session;
> struct perf_evlist;
> struct perf_tool;
> +struct option;
> struct record_opts;
> struct auxtrace_info_event;
>
> +enum itrace_period_type {
> + PERF_ITRACE_PERIOD_INSTRUCTIONS,
> + PERF_ITRACE_PERIOD_TICKS,
> + PERF_ITRACE_PERIOD_NANOSECS,
> +};
> +
> +/**
> + * struct itrace_synth_opts - AUX area tracing synthesis options.
> + * @set: indicates whether or not options have been set
> + * @inject: indicates the event (not just the sample) must be fully synthesized
> + * because 'perf inject' will write it out
> + * @instructions: whether to synthesize 'instructions' events
> + * @branches: whether to synthesize 'branches' events
> + * @errors: whether to synthesize decoder error events
> + * @dont_decode: whether to skip decoding entirely
> + * @log: write a decoding log
> + * @calls: limit branch samples to calls (can be combined with @returns)
> + * @returns: limit branch samples to returns (can be combined with @calls)
> + * @callchain: add callchain to 'instructions' events
> + * @callchain_sz: maximum callchain size
> + * @period: 'instructions' events period
> + * @period_type: 'instructions' events period type
> + */
> +struct itrace_synth_opts {
> + bool set;
> + bool inject;
> + bool instructions;
> + bool branches;
> + bool errors;
> + bool dont_decode;
> + bool log;
> + bool calls;
> + bool returns;
> + bool callchain;
> + unsigned int callchain_sz;
> + unsigned long long period;
> + enum itrace_period_type period_type;
> +};
> +
> /**
> * struct auxtrace - session callbacks to allow AUX area data decoding.
> * @process_event: lets the decoder see all session events
> @@ -186,6 +226,9 @@ int perf_event__synthesize_auxtrace_info(struct auxtrace_record *itr,
> struct perf_tool *tool,
> struct perf_session *session,
> perf_event__handler_t process);
> +int itrace_parse_synth_opts(const struct option *opt, const char *str,
> + int unset);
> +void itrace_synth_opts__set_default(struct itrace_synth_opts *synth_opts);
>
> static inline int auxtrace__process_event(struct perf_session *session,
> union perf_event *event,
> diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
> index 8a69d3b..9ed5135 100644
> --- a/tools/perf/util/session.h
> +++ b/tools/perf/util/session.h
> @@ -16,12 +16,14 @@ struct ip_callchain;
> struct thread;
>
> struct auxtrace;
> +struct itrace_synth_opts;
>
> struct perf_session {
> struct perf_header header;
> struct machines machines;
> struct perf_evlist *evlist;
> struct auxtrace *auxtrace;
> + struct itrace_synth_opts *itrace_synth_opts;
> struct trace_event tevent;
> bool repipe;
> bool one_mmap;
> --
> 1.9.1
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