From: Russ Anderson Date: Tue, 18 May 2010 22:52:40 +0000 (-0500) Subject: perf record: remove unneeded gettimeofday() call X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ef365cefbc53d8674a18520a1d4c2e5590127299;p=linux-beck.git 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 Cc: Peter Zijlstra Cc: Stephane Eranian LKML-Reference: <20100518225240.GC25589@sgi.com> Signed-off-by: Russ Anderson Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 66b8ecd22cfe..e67226981834 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++;