perf record: remove unneeded gettimeofday() call

Perf record repeatedly calls gettimeofday() which adds noise to the performance
measurements.  Since gettimeofday() is only used for the error printf, delete
it.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <20100518225240.GC25589@sgi.com>
Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 1 insertions, 16 deletions

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 66b8ecd22cf..e6722698183 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -65,9 +65,6 @@ static bool			multiplex			=  false;
 static int                      multiplex_fd                    =     -1;
 
 static long                     samples                         =      0;
-static struct timeval           last_read;
-static struct timeval           this_read;
-
 static u64                      bytes_written                   =      0;
 
 static struct pollfd            *event_array;
@@ -147,8 +144,6 @@ static void mmap_read(struct mmap_data *md)
         void *buf;
         int diff;
 
-        gettimeofday(&this_read, NULL);
-
         /*
          * If we're further behind than half the buffer, there's a chance
          * the writer will bite our tail and mess up the samples under us.
@@ -159,23 +154,13 @@ static void mmap_read(struct mmap_data *md)
          */
         diff = head - old;
         if (diff < 0) {
-                struct timeval iv;
-                unsigned long msecs;
-
-                timersub(&this_read, &last_read, &iv);
-                msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
-
-                fprintf(stderr, "WARNING: failed to keep up with mmap data."
-                                "  Last read %lu msecs ago.\n", msecs);
-
+                fprintf(stderr, "WARNING: failed to keep up with mmap data\n");
                 /*
                  * head points to a known good entry, start there.
                  */
                 old = head;
         }
 
-        last_read = this_read;
-
         if (old != head)
                 samples++;