struct perf_session *perf_session__new(const char *filename, int mode, bool force)
{
size_t len = filename ? strlen(filename) + 1 : 0;
struct perf_session *self = zalloc(sizeof(*self) + len);
if (self == NULL)
goto out;
if (perf_header__init(&self->header) < 0)
goto out_free;
memcpy(self->filename, filename, len);
self->threads = RB_ROOT;
self->last_match = NULL;
self->mmap_window = 32;
self->cwd = NULL;
self->cwdlen = 0;
self->unknown_events = 0;
map_groups__init(&self->kmaps);
if (mode == O_RDONLY) {
if (perf_session__open(self, force) < 0)
goto out_delete;
} else if (mode == O_WRONLY) {
/*
* In O_RDONLY mode this will be performed when reading the
* kernel MMAP event, in event__process_mmap().
*/
if (perf_session__create_kernel_maps(self) < 0)
goto out_delete;
}
self->sample_type = perf_header__sample_type(&self->header);
out:
return self;
out_free:
free(self);
return NULL;
out_delete:
perf_session__delete(self);
return NULL;
}
static int __cmd_trace(void)
{
int ret, rc = EXIT_FAILURE;
unsigned long offset = 0;
unsigned long head = 0;
struct stat perf_stat;
event_t *event;
uint32_t size;
char *buf;
trace_report();
register_idle_thread(&threads, &last_match);
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;
}
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) {
unsigned long shift = page_size * (head / page_size);
int res;
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;
}
