diff --git a/Documentation/perf_counter/builtin-record.c b/Documentation/perf_counter/builtin-record.c index fa625258315e..efa2eb498e9c 100644 --- a/Documentation/perf_counter/builtin-record.c +++ b/Documentation/perf_counter/builtin-record.c @@ -67,6 +67,8 @@ static unsigned int mmap_read_head(struct mmap_data *md) static long events; static struct timeval last_read, this_read; +static __u64 bytes_written; + static void mmap_read(struct mmap_data *md) { unsigned int head = mmap_read_head(md); @@ -114,28 +116,34 @@ static void mmap_read(struct mmap_data *md) buf = &data[old & md->mask]; size = md->mask + 1 - (old & md->mask); old += size; + while (size) { int ret = write(output, buf, size); - if (ret < 0) { - perror("failed to write"); - exit(-1); - } + + if (ret < 0) + die("failed to write"); + size -= ret; buf += ret; + + bytes_written += ret; } } buf = &data[old & md->mask]; size = head - old; old += size; + while (size) { int ret = write(output, buf, size); - if (ret < 0) { - perror("failed to write"); - exit(-1); - } + + if (ret < 0) + die("failed to write"); + size -= ret; buf += ret; + + bytes_written += ret; } md->prev = old; @@ -467,8 +475,14 @@ static int __cmd_record(int argc, const char **argv) ret = poll(event_array, nr_poll, 100); } - - fprintf(stderr, "[ perf record: Captured and wrote %ld events. ]\n", events); + /* + * Approximate RIP event size: 24 bytes. + */ + fprintf(stderr, + "[ perf record: Captured and wrote %.3f MB %s (~%lld events) ]\n", + (double)bytes_written / 1024.0 / 1024.0, + output_name, + bytes_written / 24); return 0; }