Re: [PATCH V2 3/8] perf tools: Add time conversion event

[Adrian Hunter <adrian.hunter@intel.com>]

On 08/03/16 10:38, Adrian Hunter wrote:
> Intel PT uses the time members from the perf_event_mmap_page
> to convert between TSC and perf time.
> 
> Due to a lack of foresight when Intel PT was implemented,
> those time members were recorded in the (implementation
> dependent) AUXTRACE_INFO event, the structure of which is
> generally inaccessible outside of the Intel PT decoder.
> However now the conversion between TSC and perf time is needed
> when processing a jitdump file when Intel PT has been used for
> tracing.
> 
> So add a user event to record the time members.  'perf record'
> will synthesize the event if the information is available.
> And session processing will put a copy of the event on the
> session so that tools like 'perf inject' can easily access it.
> 
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>

This patch (patch 3) and the V2 versions of patches 6 and 7 i.e.

[PATCH V2 3/8] perf tools: Add time conversion event
[PATCH V2 6/8] perf jit: Add support for using TSC as a timestamp
[PATCH V2 7/8] perf intel-pt/bts: Define JITDUMP_USE_ARCH_TIMESTAMP

still apply.  Do you have any comments?

> ---
> 
> Changes in V2:
> 
> 	Fixed "From" and "Signed-off-by" email addresses
> 
>  tools/perf/arch/x86/util/tsc.c | 31 +++++++++++++++++++++++++++++++
>  tools/perf/builtin-inject.c    |  1 +
>  tools/perf/builtin-record.c    | 15 +++++++++++++++
>  tools/perf/util/event.c        |  1 +
>  tools/perf/util/event.h        |  9 +++++++++
>  tools/perf/util/session.c      |  6 ++++++
>  tools/perf/util/session.h      |  1 +
>  tools/perf/util/tool.h         |  1 +
>  tools/perf/util/tsc.h          | 10 ++++++++++
>  9 files changed, 75 insertions(+)
> 
> diff --git a/tools/perf/arch/x86/util/tsc.c b/tools/perf/arch/x86/util/tsc.c
> index fd2868490d00..70ff7c14bea6 100644
> --- a/tools/perf/arch/x86/util/tsc.c
> +++ b/tools/perf/arch/x86/util/tsc.c
> @@ -46,3 +46,34 @@ u64 rdtsc(void)
>  
>  	return low | ((u64)high) << 32;
>  }
> +
> +int perf_event__synth_time_conv(const struct perf_event_mmap_page *pc,
> +				struct perf_tool *tool,
> +				perf_event__handler_t process,
> +				struct machine *machine)
> +{
> +	union perf_event event = {
> +		.time_conv = {
> +			.header = {
> +				.type = PERF_RECORD_TIME_CONV,
> +				.size = sizeof(struct time_conv_event),
> +			},
> +		},
> +	};
> +	struct perf_tsc_conversion tc;
> +	int err;
> +
> +	err = perf_read_tsc_conversion(pc, &tc);
> +	if (err == -EOPNOTSUPP)
> +		return 0;
> +	if (err)
> +		return err;
> +
> +	pr_debug2("Synthesizing TSC conversion information\n");
> +
> +	event.time_conv.time_mult  = tc.time_mult;
> +	event.time_conv.time_shift = tc.time_shift;
> +	event.time_conv.time_zero  = tc.time_zero;
> +
> +	return process(tool, &event, NULL, machine);
> +}
> diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
> index c6a4f2f94ab1..29dfe68b2fb1 100644
> --- a/tools/perf/builtin-inject.c
> +++ b/tools/perf/builtin-inject.c
> @@ -761,6 +761,7 @@ int cmd_inject(int argc, const char **argv, const char *prefix __maybe_unused)
>  			.auxtrace_info	= perf_event__repipe_op2_synth,
>  			.auxtrace	= perf_event__repipe_auxtrace,
>  			.auxtrace_error	= perf_event__repipe_op2_synth,
> +			.time_conv	= perf_event__repipe_op2_synth,
>  			.finished_round	= perf_event__repipe_oe_synth,
>  			.build_id	= perf_event__repipe_op2_synth,
>  			.id_index	= perf_event__repipe_op2_synth,
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index 515510ecc76a..410035c6e300 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -29,6 +29,7 @@
>  #include "util/data.h"
>  #include "util/perf_regs.h"
>  #include "util/auxtrace.h"
> +#include "util/tsc.h"
>  #include "util/parse-branch-options.h"
>  #include "util/parse-regs-options.h"
>  #include "util/llvm-utils.h"
> @@ -512,6 +513,15 @@ static void workload_exec_failed_signal(int signo __maybe_unused,
>  
>  static void snapshot_sig_handler(int sig);
>  
> +int __weak
> +perf_event__synth_time_conv(const struct perf_event_mmap_page *pc __maybe_unused,
> +			    struct perf_tool *tool __maybe_unused,
> +			    perf_event__handler_t process __maybe_unused,
> +			    struct machine *machine __maybe_unused)
> +{
> +	return 0;
> +}
> +
>  static int record__synthesize(struct record *rec)
>  {
>  	struct perf_session *session = rec->session;
> @@ -549,6 +559,11 @@ static int record__synthesize(struct record *rec)
>  		}
>  	}
>  
> +	err = perf_event__synth_time_conv(rec->evlist->mmap[0].base, tool,
> +					  process_synthesized_event, machine);
> +	if (err)
> +		goto out;
> +
>  	if (rec->opts.full_auxtrace) {
>  		err = perf_event__synthesize_auxtrace_info(rec->itr, tool,
>  					session, process_synthesized_event);
> diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
> index 7bad5c3fa7b7..025509129cda 100644
> --- a/tools/perf/util/event.c
> +++ b/tools/perf/util/event.c
> @@ -45,6 +45,7 @@ static const char *perf_event__names[] = {
>  	[PERF_RECORD_STAT]			= "STAT",
>  	[PERF_RECORD_STAT_ROUND]		= "STAT_ROUND",
>  	[PERF_RECORD_EVENT_UPDATE]		= "EVENT_UPDATE",
> +	[PERF_RECORD_TIME_CONV]			= "TIME_CONV",
>  };
>  
>  const char *perf_event__name(unsigned int id)
> diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
> index b7ffb7ee9971..f1dafa05e8bf 100644
> --- a/tools/perf/util/event.h
> +++ b/tools/perf/util/event.h
> @@ -232,6 +232,7 @@ enum perf_user_event_type { /* above any possible kernel type */
>  	PERF_RECORD_STAT			= 76,
>  	PERF_RECORD_STAT_ROUND			= 77,
>  	PERF_RECORD_EVENT_UPDATE		= 78,
> +	PERF_RECORD_TIME_CONV			= 79,
>  	PERF_RECORD_HEADER_MAX
>  };
>  
> @@ -468,6 +469,13 @@ struct stat_round_event {
>  	u64				time;
>  };
>  
> +struct time_conv_event {
> +	struct perf_event_header header;
> +	u64 time_shift;
> +	u64 time_mult;
> +	u64 time_zero;
> +};
> +
>  union perf_event {
>  	struct perf_event_header	header;
>  	struct mmap_event		mmap;
> @@ -496,6 +504,7 @@ union perf_event {
>  	struct stat_config_event	stat_config;
>  	struct stat_event		stat;
>  	struct stat_round_event		stat_round;
> +	struct time_conv_event		time_conv;
>  };
>  
>  void perf_event__print_totals(void);
> diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
> index 60b3593d210d..ee1778a9c0c7 100644
> --- a/tools/perf/util/session.c
> +++ b/tools/perf/util/session.c
> @@ -409,6 +409,8 @@ void perf_tool__fill_defaults(struct perf_tool *tool)
>  		tool->stat = process_stat_stub;
>  	if (tool->stat_round == NULL)
>  		tool->stat_round = process_stat_round_stub;
> +	if (tool->time_conv == NULL)
> +		tool->time_conv = process_event_op2_stub;
>  }
>  
>  static void swap_sample_id_all(union perf_event *event, void *data)
> @@ -794,6 +796,7 @@ static perf_event__swap_op perf_event__swap_ops[] = {
>  	[PERF_RECORD_STAT]		  = perf_event__stat_swap,
>  	[PERF_RECORD_STAT_ROUND]	  = perf_event__stat_round_swap,
>  	[PERF_RECORD_EVENT_UPDATE]	  = perf_event__event_update_swap,
> +	[PERF_RECORD_TIME_CONV]		  = perf_event__all64_swap,
>  	[PERF_RECORD_HEADER_MAX]	  = NULL,
>  };
>  
> @@ -1342,6 +1345,9 @@ static s64 perf_session__process_user_event(struct perf_session *session,
>  		return tool->stat(tool, event, session);
>  	case PERF_RECORD_STAT_ROUND:
>  		return tool->stat_round(tool, event, session);
> +	case PERF_RECORD_TIME_CONV:
> +		session->time_conv = event->time_conv;
> +		return tool->time_conv(tool, event, session);
>  	default:
>  		return -EINVAL;
>  	}
> diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
> index 5f792e35d4c1..f96fc9e8c52e 100644
> --- a/tools/perf/util/session.h
> +++ b/tools/perf/util/session.h
> @@ -26,6 +26,7 @@ struct perf_session {
>  	struct itrace_synth_opts *itrace_synth_opts;
>  	struct list_head	auxtrace_index;
>  	struct trace_event	tevent;
> +	struct time_conv_event	time_conv;
>  	bool			repipe;
>  	bool			one_mmap;
>  	void			*one_mmap_addr;
> diff --git a/tools/perf/util/tool.h b/tools/perf/util/tool.h
> index 55de4cffcd4e..ac2590a3de2d 100644
> --- a/tools/perf/util/tool.h
> +++ b/tools/perf/util/tool.h
> @@ -57,6 +57,7 @@ struct perf_tool {
>  			id_index,
>  			auxtrace_info,
>  			auxtrace_error,
> +			time_conv,
>  			thread_map,
>  			cpu_map,
>  			stat_config,
> diff --git a/tools/perf/util/tsc.h b/tools/perf/util/tsc.h
> index a8b78f1b3243..280ddc067556 100644
> --- a/tools/perf/util/tsc.h
> +++ b/tools/perf/util/tsc.h
> @@ -3,10 +3,20 @@
>  
>  #include <linux/types.h>
>  
> +#include "event.h"
>  #include "../arch/x86/util/tsc.h"
>  
>  u64 perf_time_to_tsc(u64 ns, struct perf_tsc_conversion *tc);
>  u64 tsc_to_perf_time(u64 cyc, struct perf_tsc_conversion *tc);
>  u64 rdtsc(void);
>  
> +struct perf_event_mmap_page;
> +struct perf_tool;
> +struct machine;
> +
> +int perf_event__synth_time_conv(const struct perf_event_mmap_page *pc,
> +				struct perf_tool *tool,
> +				perf_event__handler_t process,
> +				struct machine *machine);
> +
>  #endif
>