From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755124Ab0EUBIw (ORCPT ); Thu, 20 May 2010 21:08:52 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:45605 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752508Ab0EUBIv (ORCPT ); Thu, 20 May 2010 21:08:51 -0400 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Russ Anderson , Ingo Molnar , Peter Zijlstra , Stephane Eranian , Arnaldo Carvalho de Melo Subject: [PATCH 1/2] perf record: remove unneeded gettimeofday() call Date: Thu, 20 May 2010 22:08:40 -0300 Message-Id: <1274404121-6115-2-git-send-email-acme@infradead.org> X-Mailer: git-send-email 1.6.2.5 In-Reply-To: <1274404121-6115-1-git-send-email-acme@infradead.org> References: <1274404121-6115-1-git-send-email-acme@infradead.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Russ Anderson 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 --- tools/perf/builtin-record.c | 17 +---------------- 1 files changed, 1 insertions(+), 16 deletions(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 66b8ecd..e672269 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++; -- 1.6.2.5