perf record: Refine capture printout

Print out the number of bytes captured, and the (estimated) number of
events the output file contains.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/Documentation/perf_counter/builtin-record.c b/Documentation/perf_counter/builtin-record.c
index fa625258315ecd71dcdb444602808a1545af4c8c..efa2eb498e9cd00b9a83f207491ebcfa4405bff1 100644 (file)
--- 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;
 }