[tip:perf/core] perf tools: Fix counter sample frequency breakage

tip-bot for Mike Galbraith
2009-10-12T07:14:18Z

Commit-ID: 7e4ff9e3e8f88de8a8536f43294cd32b4e7d9123
Gitweb: http://git.kernel.org/tip/7e4ff9e3e8f88de8a8536f43294cd32b4e7d9123
Author: Mike Galbraith <efault@gmx.de>
AuthorDate: Mon, 12 Oct 2009 07:56:03 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Mon, 12 Oct 2009 09:10:55 +0200

perf tools: Fix counter sample frequency breakage

Commit 42e59d7d19dc4b4 switched to a default sample frequency of
1KHz, which overrides any user supplied count, causing sched, top
and timechart to miss events due to their discrete events
being flagged PERF_SAMPLE_PERIOD.

Override default sample frequency when the user profides a
period count, and make both record and top honor that user
supplied option.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arjan van de Ven <arjan@infradead.org>
LKML-Reference: <1255326963.15107.2.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
tools/perf/builtin-record.c | 14 +++++++++++++-
tools/perf/builtin-top.c | 28 +++++++++++++++++++++-------
2 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 59af03d..4e3a374 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -26,7 +26,7 @@

static int fd[MAX_NR_CPUS][MAX_COUNTERS];

-static long default_interval = 100000;
+static long default_interval = 0;

static int nr_cpus = 0;
static unsigned int page_size;
@@ -730,6 +730,18 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
}

+ /*
+ * User specified count overrides default frequency.
+ */
+ if (default_interval)
+ freq = 0;
+ else if (freq) {
+ default_interval = freq;
+ } else {
+ fprintf(stderr, "frequency and count are zero, aborting\n");
+ exit(EXIT_FAILURE);
+ }
+
for (counter = 0; counter < nr_counters; counter++) {
if (attrs[counter].sample_period)
continue;
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index d978dc9..c0f69e8 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -57,7 +57,7 @@ static int fd[MAX_NR_CPUS][MAX_COUNTERS];

static int system_wide = 0;

-static int default_interval = 100000;
+static int default_interval = 0;

static int count_filter = 5;
static int print_entries = 15;
@@ -975,7 +975,13 @@ static void start_counter(int i, int counter)
attr = attrs + counter;

attr->sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_TID;
- attr->freq = freq;
+
+ if (freq) {
+ attr->sample_type |= PERF_SAMPLE_PERIOD;
+ attr->freq = 1;
+ attr->sample_freq = freq;
+ }
+
attr->inherit = (cpu < 0) && inherit;

try_again:
@@ -1130,11 +1136,6 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
if (argc)
usage_with_options(top_usage, options);

- if (freq) {
- default_interval = freq;
- freq = 1;
- }
-
/* CPU and PID are mutually exclusive */
if (target_pid != -1 && profile_cpu != -1) {
printf("WARNING: PID switch overriding CPU\n");
@@ -1151,6 +1152,19 @@ int cmd_top(int argc, const char **argv, const char *prefix __used)
parse_symbols();
parse_source(sym_filter_entry);

+
+ /*
+ * User specified count overrides default frequency.
+ */
+ if (default_interval)
+ freq = 0;
+ else if (freq) {
+ default_interval = freq;
+ } else {
+ fprintf(stderr, "frequency and count are zero, aborting\n");
+ exit(EXIT_FAILURE);
+ }
+
/*
* Fill in the ones not specifically initialized via -c:
*/