perf report: Add support for profiling JIT generated code

This patch adds support for profiling JIT generated code to 'perf
report'. A JIT compiler is required to generate a "/tmp/perf-$PID.map"
symbols map that is parsed when looking and displaying symbols.

Thanks to Peter Zijlstra for his help with this patch!

Example "perf report" output with the Jato JIT:

 #
 # (40311 samples)
 #
 # Overhead           Command  Shared Object              Symbol
 # ........  ................  .........................  ......
 #
     97.80%              jato  /tmp/perf-11915.map        [.] Fibonacci.fib(I)I
      0.56%              jato  00000000b7fa023b           0x000000b7fa023b
      0.45%              jato  /tmp/perf-11915.map        [.] Fibonacci.main([Ljava/lang/String;)V
      0.38%              jato  [kernel]                   [k] get_page_from_freelist
      0.06%              jato  [kernel]                   [k] kunmap_atomic
      0.05%              jato  ./jato                     [.] utf8Hash
      0.04%              jato  ./jato                     [.] executeJava
      0.04%              jato  ./jato                     [.] defineClass

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: a.p.zijlstra@chello.nl
Cc: acme@redhat.com
LKML-Reference: <Pine.LNX.4.64.0906082111590.12407@melkki.cs.Helsinki.FI>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 14 insertions, 1 deletions

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index f053a7463dcf..61d871849b44 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -209,6 +209,11 @@ static uint64_t vdso__map_ip(struct map *map, uint64_t ip)
 	return ip;
 }
 
+static inline int is_anon_memory(const char *filename)
+{
+     return strcmp(filename, "//anon") == 0;
+}
+
 static struct map *map__new(struct mmap_event *event)
 {
 	struct map *self = malloc(sizeof(*self));
@@ -216,6 +221,7 @@ static struct map *map__new(struct mmap_event *event)
 	if (self != NULL) {
 		const char *filename = event->filename;
 		char newfilename[PATH_MAX];
+		int anon;
 
 		if (cwd) {
 			int n = strcommon(filename);
@@ -227,6 +233,13 @@ static struct map *map__new(struct mmap_event *event)
 			}
 		}
 
+		anon = is_anon_memory(filename);
+
+		if (anon) {
+			snprintf(newfilename, sizeof(newfilename), "/tmp/perf-%d.map", event->pid);
+			filename = newfilename;
+		}
+
 		self->start = event->start;
 		self->end   = event->start + event->len;
 		self->pgoff = event->pgoff;
@@ -235,7 +248,7 @@ static struct map *map__new(struct mmap_event *event)
 		if (self->dso == NULL)
 			goto out_delete;
 
-		if (self->dso == vdso)
+		if (self->dso == vdso || anon)
 			self->map_ip = vdso__map_ip;
 		else
 			self->map_ip = map__map_ip;