perf tools: Unify perf.data mapping and events handling

This librarizes the perf.data file mapping and handling in various
perf tools, roughly reducing the amount of code and fixing the
places that mmap from beginning of the file whereas we want to mmap
from the beginning of the data, leading to page fault because the
mmap window is too small since the trace info are written in the
file too.

TODO:

 - convert perf timechart too

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arjan van de Ven <arjan@infradead.org>
LKML-Reference: <20091007104729.GD5043@nowhere>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 18 insertions, 111 deletions

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index d9abb4ae5f7..fb3f3c22021 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -12,11 +12,9 @@
 #include "util/debug.h"
 
 #include "util/trace-event.h"
+#include "util/data_map.h"
 
 static char		const *input_name = "perf.data";
-static int		input;
-static unsigned long	page_size;
-static unsigned long	mmap_window = 32;
 
 static unsigned long	total = 0;
 static unsigned long	total_comm = 0;
@@ -27,6 +25,9 @@ static struct thread	*last_match;
 static struct perf_header *header;
 static u64		sample_type;
 
+static char		*cwd;
+static int		cwdlen;
+
 
 static int
 process_comm_event(event_t *event, unsigned long offset, unsigned long head)
@@ -112,125 +113,32 @@ process_sample_event(event_t *event, unsigned long offset, unsigned long head)
 	return 0;
 }
 
-static int
-process_event(event_t *event, unsigned long offset, unsigned long head)
+static int sample_type_check(u64 type)
 {
-	trace_event(event);
-
-	switch (event->header.type) {
-	case PERF_RECORD_MMAP ... PERF_RECORD_LOST:
-		return 0;
-
-	case PERF_RECORD_COMM:
-		return process_comm_event(event, offset, head);
-
-	case PERF_RECORD_EXIT ... PERF_RECORD_READ:
-		return 0;
+	sample_type = type;
 
-	case PERF_RECORD_SAMPLE:
-		return process_sample_event(event, offset, head);
-
-	case PERF_RECORD_MAX:
-	default:
+	if (!(sample_type & PERF_SAMPLE_RAW)) {
+		fprintf(stderr,
+			"No trace sample to read. Did you call perf record "
+			"without -R?");
 		return -1;
 	}
 
 	return 0;
 }
 
+static struct perf_file_handler file_handler = {
+	.process_sample_event	= process_sample_event,
+	.process_comm_event	= process_comm_event,
+	.sample_type_check	= sample_type_check,
+};
+
 static int __cmd_trace(void)
 {
-	int ret, rc = EXIT_FAILURE;
-	unsigned long offset = 0;
-	unsigned long head = 0;
-	unsigned long shift;
-	struct stat perf_stat;
-	event_t *event;
-	uint32_t size;
-	char *buf;
-
 	register_idle_thread(&threads, &last_match);
+	register_perf_file_handler(&file_handler);
 
-	input = open(input_name, O_RDONLY);
-	if (input < 0) {
-		perror("failed to open file");
-		exit(-1);
-	}
-
-	ret = fstat(input, &perf_stat);
-	if (ret < 0) {
-		perror("failed to stat file");
-		exit(-1);
-	}
-
-	if (!perf_stat.st_size) {
-		fprintf(stderr, "zero-sized file, nothing to do!\n");
-		exit(0);
-	}
-	header = perf_header__read(input);
-	head = header->data_offset;
-	sample_type = perf_header__sample_type(header);
-
-	if (!(sample_type & PERF_SAMPLE_RAW))
-		die("No trace sample to read. Did you call perf record "
-		    "without -R?");
-
-	if (load_kernel() < 0) {
-		perror("failed to load kernel symbols");
-		return EXIT_FAILURE;
-	}
-
-	shift = page_size * (head / page_size);
-	offset += shift;
-	head -= shift;
-
-remap:
-	buf = (char *)mmap(NULL, page_size * mmap_window, PROT_READ,
-			   MAP_SHARED, input, offset);
-	if (buf == MAP_FAILED) {
-		perror("failed to mmap file");
-		exit(-1);
-	}
-
-more:
-	event = (event_t *)(buf + head);
-
-	if (head + event->header.size >= page_size * mmap_window) {
-		int res;
-
-		shift = page_size * (head / page_size);
-		res = munmap(buf, page_size * mmap_window);
-		assert(res == 0);
-
-		offset += shift;
-		head -= shift;
-		goto remap;
-	}
-
-	size = event->header.size;
-
-	if (!size || process_event(event, offset, head) < 0) {
-
-		/*
-		 * assume we lost track of the stream, check alignment, and
-		 * increment a single u64 in the hope to catch on again 'soon'.
-		 */
-
-		if (unlikely(head & 7))
-			head &= ~7ULL;
-
-		size = 8;
-	}
-
-	head += size;
-
-	if (offset + head < (unsigned long)perf_stat.st_size)
-		goto more;
-
-	rc = EXIT_SUCCESS;
-	close(input);
-
-	return rc;
+	return mmap_dispatch_perf_file(&header, input_name, 0, 0, &cwdlen, &cwd);
 }
 
 static const char * const annotate_usage[] = {
@@ -249,7 +157,6 @@ static const struct option options[] = {
 int cmd_trace(int argc, const char **argv, const char *prefix __used)
 {
 	symbol__init();
-	page_size = getpagesize();
 
 	argc = parse_options(argc, argv, options, annotate_usage, 0);
 	if (argc) {