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Commit 8755a8f2 authored by Arjan van de Ven's avatar Arjan van de Ven Committed by Ingo Molnar
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perf: Store trace event name/id pairs in perf.data 



The trace event name<->id mapping is dynamic for each kernel
compile. In order for perf.data to be useable outside the actual
system, we thus need to store a table of this mapping for later
use.

This patch adds this table to perf.data, and provides helper
functions for lookup up fields from this table.

To avoid mistakes, lookup-from-table is kept completely seprate
from lookup-from-local-debugfs.

Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090912130405.6960d099@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 393b2ad8

tools/perf/util/header.c

+59 −0
Original line number Diff line number Diff line
@@ -86,6 +86,44 @@ void perf_header__add_attr(struct perf_header *self, 
	self->attr[pos] = attr;

}



struct perf_trace_event_type {

	u64	event_id;

	char	name[64];

};



static int event_count;

static struct perf_trace_event_type *events;



void perf_header__push_event(u64 id, const char *name)

{

	if (strlen(name) > 64)

		printf("Event %s will be truncated\n", name);



	if (!events) {

		events = malloc(sizeof(struct perf_trace_event_type));

		if (!events)

			die("nomem");

	} else {

		events = realloc(events, (event_count + 1) * sizeof(struct perf_trace_event_type));

		if (!events)

			die("nomem");

	}

	memset(&events[event_count], 0, sizeof(struct perf_trace_event_type));

	events[event_count].event_id = id;

	strncpy(events[event_count].name, name, 63);

	event_count++;

}



char *perf_header__find_event(u64 id)

{

	int i;

	for (i = 0 ; i < event_count; i++) {

		if (events[i].event_id == id)

			return events[i].name;

	}

	return NULL;

}



static const char *__perf_magic = "PERFFILE";



#define PERF_MAGIC	(*(u64 *)__perf_magic)
@@ -106,6 +144,7 @@ struct perf_file_header { 
	u64				attr_size;

	struct perf_file_section	attrs;

	struct perf_file_section	data;

	struct perf_file_section	event_types;

};



static void do_write(int fd, void *buf, size_t size)
@@ -154,6 +193,11 @@ void perf_header__write(struct perf_header *self, int fd) 
		do_write(fd, &f_attr, sizeof(f_attr));

	}



	self->event_offset = lseek(fd, 0, SEEK_CUR);

	self->event_size = event_count * sizeof(struct perf_trace_event_type);

	if (events)

		do_write(fd, events, self->event_size);





	self->data_offset = lseek(fd, 0, SEEK_CUR);
@@ -169,6 +213,10 @@ void perf_header__write(struct perf_header *self, int fd) 
			.offset = self->data_offset,

			.size	= self->data_size,

		},

		.event_types = {

			.offset = self->event_offset,

			.size	= self->event_size,

		},

	};



	lseek(fd, 0, SEEK_SET);
@@ -234,6 +282,17 @@ struct perf_header *perf_header__read(int fd) 
		lseek(fd, tmp, SEEK_SET);

	}



	if (f_header.event_types.size) {

		lseek(fd, f_header.event_types.offset, SEEK_SET);

		events = malloc(f_header.event_types.size);

		if (!events)

			die("nomem");

		do_read(fd, events, f_header.event_types.size);

		event_count =  f_header.event_types.size / sizeof(struct perf_trace_event_type);

	}

	self->event_offset = f_header.event_types.offset;

	self->event_size   = f_header.event_types.size;



	self->data_offset = f_header.data.offset;

	self->data_size   = f_header.data.size;

tools/perf/util/header.h

+6 −0
Original line number Diff line number Diff line
@@ -19,6 +19,8 @@ struct perf_header { 
	s64 attr_offset;

	u64 data_offset;

	u64 data_size;

	u64 event_offset;

	u64 event_size;

};



struct perf_header *perf_header__read(int fd);
@@ -27,6 +29,10 @@ void perf_header__write(struct perf_header *self, int fd); 
void perf_header__add_attr(struct perf_header *self,

			   struct perf_header_attr *attr);



void perf_header__push_event(u64 id, const char *name);

char *perf_header__find_event(u64 id);





struct perf_header_attr *

perf_header_attr__new(struct perf_counter_attr *attr);

void perf_header_attr__add_id(struct perf_header_attr *self, u64 id);

tools/perf/util/parse-events.c

+25 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
#include "exec_cmd.h"

#include "string.h"

#include "cache.h"

#include "header.h"



int					nr_counters;
@@ -687,11 +688,35 @@ parse_event_symbols(const char **str, struct perf_counter_attr *attr) 
	return ret;

}



static void store_event_type(const char *orgname)

{

	char filename[PATH_MAX], *c;

	FILE *file;

	int id;



	sprintf(filename, "/sys/kernel/debug/tracing/events/%s/id", orgname);

	c = strchr(filename, ':');

	if (c)

		*c = '/';



	file = fopen(filename, "r");

	if (!file)

		return;

	if (fscanf(file, "%i", &id) < 1)

		die("cannot store event ID");

	fclose(file);

	perf_header__push_event(id, orgname);

}





int parse_events(const struct option *opt __used, const char *str, int unset __used)

{

	struct perf_counter_attr attr;

	enum event_result ret;



	if (strchr(str, ':'))

		store_event_type(str);



	for (;;) {

		if (nr_counters == MAX_COUNTERS)

			return -1;