[PATCH 1/3] perf tools: Recognize hugetlb mapping as anon mapping

From: Wang Nan
Date: Fri Sep 02 2016 - 10:00:24 EST


Hugetlbfs mapping should be recognized as anon mapping so user has
a chance to create /tmp/perf-<pid>.map file for symbol resolving. This
patch utilizes MAP_HUGETLB to identify hugetlb mapping.

After this patch, if perf is started before the program uses huge pages
starting, perf is able to recognize hugetlb mapping as anon mapping.

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Signed-off-by: Hou Pengyang <houpengyang@xxxxxxxxxx>
Cc: He Kuang <hekuang@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/map.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 728129a..a42010d 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -6,6 +6,7 @@
#include <string.h>
#include <stdio.h>
#include <unistd.h>
+#include <sys/mman.h>
#include "map.h"
#include "thread.h"
#include "strlist.h"
@@ -24,9 +25,10 @@ const char *map_type__name[MAP__NR_TYPES] = {
[MAP__VARIABLE] = "Variables",
};

-static inline int is_anon_memory(const char *filename)
+static inline int is_anon_memory(const char *filename, u32 flags)
{
- return !strcmp(filename, "//anon") ||
+ return flags & MAP_HUGETLB ||
+ !strcmp(filename, "//anon") ||
!strncmp(filename, "/dev/zero", sizeof("/dev/zero") - 1) ||
!strncmp(filename, "/anon_hugepage", sizeof("/anon_hugepage") - 1);
}
@@ -155,7 +157,7 @@ struct map *map__new(struct machine *machine, u64 start, u64 len,
int anon, no_dso, vdso, android;

android = is_android_lib(filename);
- anon = is_anon_memory(filename);
+ anon = is_anon_memory(filename, flags);
vdso = is_vdso_map(filename);
no_dso = is_no_dso_memory(filename);

--
1.8.3.4