perf record/report: Add call graph / call chain profiling

Add the first steps of call-graph profiling:

 - add the -c (--call-graph) option to perf record
 - parse the call-graph record and printout out under -D (--dump-trace)

The call-graph data is not put into the histogram yet, but it
can be seen that it's being processed correctly:

0x3ce0 [0x38]: event: 35
.
. ... raw event: size 56 bytes
.  0000:  23 00 00 00 05 00 38 00 d4 df 0e 81 ff ff ff ff  #.....8........
.  0010:  60 0b 00 00 60 0b 00 00 03 00 00 00 01 00 02 00  `...`..........
.  0020:  d4 df 0e 81 ff ff ff ff a0 61 ed 41 36 00 00 00  .........a.A6..
.  0030:  04 92 e6 41 36 00 00 00                          .a.A6..
.
0x3ce0 [0x38]: PERF_EVENT (IP, 5): 2912: 0xffffffff810edfd4 period: 1
... chain: u:2, k:1, nr:3
.....  0: 0xffffffff810edfd4
.....  1: 0x3641ed61a0
.....  2: 0x3641e69204
 ... thread: perf:2912
 ...... dso: [kernel]

This shows a 3-entry call-graph: with 1 kernel-space and two user-space
entries

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Arjan van de Ven <arjan@infradead.org>
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>

2 files changed, 53 insertions, 12 deletions

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 0f5771f615da..a177a591b52c 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -37,6 +37,7 @@ static pid_t			target_pid			= -1;
 static int                      inherit                         = 1;
 static int                      force                           = 0;
 static int                      append_file                     = 0;
+static int                      call_graph                      = 0;
 static int                      verbose                         = 0;
 
 static long                     samples;
@@ -351,11 +352,16 @@ static void create_counter(int counter, int cpu, pid_t pid)
         int track = 1;
 
         attr->sample_type       = PERF_SAMPLE_IP | PERF_SAMPLE_TID;
+
         if (freq) {
                 attr->sample_type       |= PERF_SAMPLE_PERIOD;
                 attr->freq              = 1;
                 attr->sample_freq       = freq;
         }
+
+        if (call_graph)
+                attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
+
         attr->mmap              = track;
         attr->comm              = track;
         attr->inherit           = (cpu < 0) && inherit;
@@ -555,6 +561,8 @@ static const struct option options[] = {
                     "profile at this frequency"),
         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
                     "number of mmap data pages"),
+        OPT_BOOLEAN('g', "call-graph", &call_graph,
+                    "do call-graph (stack chain/backtrace) recording"),
         OPT_BOOLEAN('v', "verbose", &verbose,
                     "be more verbose (show counter open errors, etc)"),
         OPT_END()
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 37515da637f7..aebba5659345 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -36,6 +36,7 @@ static int		show_mask = SHOW_KERNEL | SHOW_USER | SHOW_HV;
 
 static int              dump_trace = 0;
 #define dprintf(x...)   do { if (dump_trace) printf(x); } while (0)
+#define cdprintf(x...)  do { if (dump_trace) color_fprintf(stdout, color, x); } while (0)
 
 static int              verbose;
 static int              full_paths;
@@ -43,11 +44,19 @@ static int		full_paths;
 static unsigned long    page_size;
 static unsigned long    mmap_window = 32;
 
+struct ip_chain_event {
+        __u16 nr;
+        __u16 hv;
+        __u16 kernel;
+        __u16 user;
+        __u64 ips[];
+};
+
 struct ip_event {
         struct perf_event_header header;
         __u64 ip;
         __u32 pid, tid;
-        __u64 period;
+        unsigned char __more_data[];
 };
 
 struct mmap_event {
@@ -944,9 +953,13 @@ process_overflow_event(event_t *event, unsigned long offset, unsigned long head)
         __u64 ip = event->ip.ip;
         __u64 period = 1;
         struct map *map = NULL;
+        void *more_data = event->ip.__more_data;
+        struct ip_chain_event *chain;
 
-        if (event->header.type & PERF_SAMPLE_PERIOD)
-                period = event->ip.period;
+        if (event->header.type & PERF_SAMPLE_PERIOD) {
+                period = *(__u64 *)more_data;
+                more_data += sizeof(__u64);
+        }
 
         dprintf("%p [%p]: PERF_EVENT (IP, %d): %d: %p period: %Ld\n",
                 (void *)(offset + head),
@@ -956,6 +969,22 @@ process_overflow_event(event_t *event, unsigned long offset, unsigned long head)
                 (void *)(long)ip,
                 (long long)period);
 
+        if (event->header.type & PERF_SAMPLE_CALLCHAIN) {
+                int i;
+
+                chain = (void *)more_data;
+
+                if (dump_trace) {
+                        dprintf("... chain: u:%d, k:%d, nr:%d\n",
+                                chain->user,
+                                chain->kernel,
+                                chain->nr);
+
+                        for (i = 0; i < chain->nr; i++)
+                                dprintf("..... %2d: %p\n", i, (void *)chain->ips[i]);
+                }
+        }
+
         dprintf(" ... thread: %s:%d\n", thread->comm, thread->pid);
 
         if (thread == NULL) {
@@ -1098,30 +1127,34 @@ process_period_event(event_t *event, unsigned long offset, unsigned long head)
 static void trace_event(event_t *event)
 {
         unsigned char *raw_event = (void *)event;
+        char *color = PERF_COLOR_BLUE;
         int i, j;
 
         if (!dump_trace)
                 return;
 
-        dprintf(".\n. ... raw event: size %d bytes\n", event->header.size);
+        dprintf(".");
+        cdprintf("\n. ... raw event: size %d bytes\n", event->header.size);
 
         for (i = 0; i < event->header.size; i++) {
-                if ((i & 15) == 0)
-                        dprintf(".  %04x: ", i);
+                if ((i & 15) == 0) {
+                        dprintf(".");
+                        cdprintf("  %04x: ", i);
+                }
 
-                dprintf(" %02x", raw_event[i]);
+                cdprintf(" %02x", raw_event[i]);
 
                 if (((i & 15) == 15) || i == event->header.size-1) {
-                        dprintf("  ");
+                        cdprintf("  ");
                         for (j = 0; j < 15-(i & 15); j++)
-                                dprintf("   ");
+                                cdprintf("   ");
                         for (j = 0; j < (i & 15); j++) {
                                 if (isprint(raw_event[i-15+j]))
-                                        dprintf("%c", raw_event[i-15+j]);
+                                        cdprintf("%c", raw_event[i-15+j]);
                                 else
-                                        dprintf(".");
+                                        cdprintf(".");
                         }
-                        dprintf("\n");
+                        cdprintf("\n");
                 }
         }
         dprintf(".\n");