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

[Arnaldo Carvalho de Melo <acme@kernel.org>]

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