perf record, top: Implement --freq

Support frequency-based profiling and make it the default.

(Also add a Hz printout in perf top.)

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 9 insertions, 1 deletions

diff --git a/Documentation/perf_counter/builtin-record.c b/Documentation/perf_counter/builtin-record.c
index 7f2d7ce94075..e2301f39e551 100644
--- a/Documentation/perf_counter/builtin-record.c
+++ b/Documentation/perf_counter/builtin-record.c
@@ -27,6 +27,7 @@ static int			fd[MAX_NR_CPUS][MAX_COUNTERS];
 static int                      nr_cpus                         = 0;
 static unsigned int             page_size;
 static unsigned int             mmap_pages                      = 128;
+static int                      freq                            = 0;
 static int                      output;
 static const char               *output_name                    = "perf.data";
 static int                      group                           = 0;
@@ -347,9 +348,10 @@ static void create_counter(int counter, int cpu, pid_t pid)
         attr.config             = event_id[counter];
         attr.sample_period      = event_count[counter];
         attr.sample_type        = PERF_SAMPLE_IP | PERF_SAMPLE_TID;
+        attr.freq               = freq;
         attr.mmap               = track;
         attr.comm               = track;
-        attr.inherit    = (cpu < 0) && inherit;
+        attr.inherit            = (cpu < 0) && inherit;
 
         track = 0; /* only the first counter needs these */
 
@@ -520,6 +522,8 @@ static const struct option options[] = {
                     "output file name"),
         OPT_BOOLEAN('i', "inherit", &inherit,
                     "child tasks inherit counters"),
+        OPT_INTEGER('F', "freq", &freq,
+                    "profile at this frequency"),
         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
                     "number of mmap data pages"),
         OPT_END()
@@ -540,6 +544,10 @@ int cmd_record(int argc, const char **argv, const char *prefix)
                 event_id[0] = 0;
         }
 
+        if (freq) {
+                default_interval = freq;
+                freq = 1;
+        }
         for (counter = 0; counter < nr_counters; counter++) {
                 if (event_count[counter])
                         continue;