perf tools: Recognize hugetlb mapping as anon mapping

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 a program starts using huge
pages (so perf gets MMAP2 events from kernel), perf is able to recognize
hugetlb mapping as anon mapping.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/1473137909-142064-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 0c54adb..d51a125 100644 (file)
--- 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 +25,15 @@ 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") ||
+       u32 anon_flags = 0;
+
+#ifdef MAP_HUGETLB
+       anon_flags |= MAP_HUGETLB;
+#endif
+       return flags & anon_flags ||
+              !strcmp(filename, "//anon") ||
               !strncmp(filename, "/dev/zero", sizeof("/dev/zero") - 1) ||
               !strncmp(filename, "/anon_hugepage", sizeof("/anon_hugepage") - 1);
 }
@@ -155,7 +162,7 @@ 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);