From: Chenggang Qin <chenggang....@taobao.com>
Vdso is only one in a system. It is not necessory to traverse the
macine->user_dsos list when looking for the dso of vdso.
The flag vdso_found should be replaced by a pointor that point to the dso of
vdso. If the pointer is NULL, dso of vdso have not been created. Else, the
pointor can be returned directly in function vdso__dso_findnew().
The list traversing can be avoided by this method.
Thanks.
Cc: David Ahern <dsah...@gmail.com>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: Arnaldo Carvalho de Melo <a...@ghostprotocols.net>
Cc: Arjan van de Ven <ar...@linux.intel.com>
Cc: Namhyung Kim <namhy...@gmail.com>
Cc: Yanmin Zhang <yanmin.zh...@intel.com>
Cc: Wu Fengguang <fengguang...@intel.com>
Cc: Mike Galbraith <efa...@gmx.de>
Cc: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Chenggang Qin <chenggang....@taobao.com>
---
tools/perf/util/vdso.c | 22 ++++++++--------------
1 files changed, 8 insertions(+), 14 deletions(-)
diff --git a/tools/perf/util/vdso.c b/tools/perf/util/vdso.c
index 3915982..8022ef0 100644
--- a/tools/perf/util/vdso.c
+++ b/tools/perf/util/vdso.c
@@ -13,7 +13,7 @@
#include "symbol.h"
#include "linux/string.h"
-static bool vdso_found;
+static struct dso *vdso_dso = NULL;
static char vdso_file[] = "/tmp/perf-vdso.so-XXXXXX";
static int find_vdso_map(void **start, void **end)
@@ -55,9 +55,6 @@ static char *get_file(void)
size_t size;
int fd;
- if (vdso_found)
- return vdso_file;
-
if (find_vdso_map(&start, &end))
return NULL;
@@ -79,33 +76,30 @@ static char *get_file(void)
out:
free(buf);
- vdso_found = (vdso != NULL);
return vdso;
}
void vdso__exit(void)
{
- if (vdso_found)
+ if (vdso_dso)
unlink(vdso_file);
}
struct dso *vdso__dso_findnew(struct list_head *head)
{
- struct dso *dso = dsos__find(head, VDSO__MAP_NAME, true);
-
- if (!dso) {
+ if (!vdso_dso) {
char *file;
file = get_file();
if (!file)
return NULL;
- dso = dso__new(VDSO__MAP_NAME);
- if (dso != NULL) {
- dsos__add(head, dso);
- dso__set_long_name(dso, file);
+ vdso_dso = dso__new(VDSO__MAP_NAME);
+ if (vdso_dso != NULL) {
+ dsos__add(head, vdso_dso);
+ dso__set_long_name(vdso_dso, file);
}
}
- return dso;
+ return vdso_dso;
}
--
1.7.8.rc2.5.g815b
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
