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>

1 files changed, 21 insertions, 7 deletions

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index d978dc99236c..c0f69e80b2cc 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:
          */