[PATCH 08/37] perf comm: Use atomic.h for refcounting

From: Arnaldo Carvalho de Melo
Date: Tue May 26 2015 - 12:57:04 EST


From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

Now that we have atomic.h, we should convert all of the existing
refcounts to use it.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Don Zickus <dzickus@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-quzeuy3jwsyod6e06o39cl6y@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/comm.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/comm.c b/tools/perf/util/comm.c
index b2bb59df65e1..21b7ff382c3f 100644
--- a/tools/perf/util/comm.c
+++ b/tools/perf/util/comm.c
@@ -2,24 +2,27 @@
#include "util.h"
#include <stdlib.h>
#include <stdio.h>
+#include <linux/atomic.h>

struct comm_str {
char *str;
struct rb_node rb_node;
- int ref;
+ atomic_t refcnt;
};

/* Should perhaps be moved to struct machine */
static struct rb_root comm_str_root;

-static void comm_str__get(struct comm_str *cs)
+static struct comm_str *comm_str__get(struct comm_str *cs)
{
- cs->ref++;
+ if (cs)
+ atomic_inc(&cs->refcnt);
+ return cs;
}

static void comm_str__put(struct comm_str *cs)
{
- if (!--cs->ref) {
+ if (cs && atomic_dec_and_test(&cs->refcnt)) {
rb_erase(&cs->rb_node, &comm_str_root);
zfree(&cs->str);
free(cs);
@@ -40,6 +43,8 @@ static struct comm_str *comm_str__alloc(const char *str)
return NULL;
}

+ atomic_set(&cs->refcnt, 0);
+
return cs;
}

--
2.1.0

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