[PATCH] perf symbols: Synthesize anonymous mmap events

From: Anton Blanchard
Date: Mon Aug 29 2011 - 19:15:16 EST



perf_event__synthesize_mmap_events does not create anonymous mmap
events even though the kernel does. As a result an already running
application with dynamically created code will not get profiled -
all samples end up in the unknown bucket.

This patch skips any entries with '[' in the name to avoid adding
events for special regions (eg the vsyscall page). All other
executable mmaps are assumed to be anonymous and an event is
synthesized.

Signed-off-by: Anton Blanchard <anton@xxxxxxxxx>
---

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 3c1b8a6..437f8ca 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -169,12 +169,17 @@ static int perf_event__synthesize_mmap_events(union perf_event *event,
continue;
pbf += n + 3;
if (*pbf == 'x') { /* vm_exec */
+ char anonstr[] = "//anon\n";
char *execname = strchr(bf, '/');

/* Catch VDSO */
if (execname == NULL)
execname = strstr(bf, "[vdso]");

+ /* Catch anonymous mmaps */
+ if ((execname == NULL) && !strstr(bf, "["))
+ execname = anonstr;
+
if (execname == NULL)
continue;

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/