From: Arnaldo Carvalho de Melo <acme@infradead.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: linux-kernel@vger.kernel.org, Russ Anderson <rja@sgi.com>,
Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <peterz@infradead.org>,
Stephane Eranian <eranian@google.com>,
Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: [PATCH 1/2] perf record: remove unneeded gettimeofday() call
Date: Thu, 20 May 2010 22:08:40 -0300 [thread overview]
Message-ID: <1274404121-6115-2-git-send-email-acme@infradead.org> (raw)
In-Reply-To: <1274404121-6115-1-git-send-email-acme@infradead.org>
From: Russ Anderson <rja@sgi.com>
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>
---
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
next prev parent reply other threads:[~2010-05-21 1:08 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-21 1:08 [GIT PULL v2 0/2] Allow disabling TUI per command in ~/.perfconfig Arnaldo Carvalho de Melo
2010-05-21 1:08 ` Arnaldo Carvalho de Melo [this message]
2010-05-21 1:08 ` [PATCH v2 2/2] perf tui: Allow disabling the TUI on a per command basis " Arnaldo Carvalho de Melo
2010-05-21 7:52 ` [GIT PULL v2 0/2] Allow disabling TUI per command " Ingo Molnar
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