[tip:perf/core] perf dso: Simplify dso_cache__read function

[tip-bot for Jiri Olsa]

Commit-ID:  cacddfe7b0804752528e8100461266ec33dc6b64
Gitweb:     https://git.kernel.org/tip/cacddfe7b0804752528e8100461266ec33dc6b64
Author:     Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Wed, 8 May 2019 15:20:01 +0200
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Tue, 28 May 2019 18:37:44 -0300

perf dso: Simplify dso_cache__read function

There's no need for the while loop now, also we can connect two (ret >
0) condition legs together.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Acked-by: Song Liu <songliubraving@xxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Song Liu <songliubraving@xxxxxx>
Cc: Stanislav Fomichev <sdf@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/20190508132010.14512-4-jolsa@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/dso.c | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 7734f50a6912..1e6a045adb8c 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -823,25 +823,20 @@ static ssize_t
 dso_cache__read(struct dso *dso, struct machine *machine,
 		u64 offset, u8 *data, ssize_t size)
 {
+	u64 cache_offset = offset & DSO__DATA_CACHE_MASK;
 	struct dso_cache *cache;
 	struct dso_cache *old;
 	ssize_t ret;
 
-	do {
-		u64 cache_offset = offset & DSO__DATA_CACHE_MASK;
-
-		cache = zalloc(sizeof(*cache) + DSO__DATA_CACHE_SIZE);
-		if (!cache)
-			return -ENOMEM;
-
-		ret = file_read(dso, machine, cache_offset, cache->data);
+	cache = zalloc(sizeof(*cache) + DSO__DATA_CACHE_SIZE);
+	if (!cache)
+		return -ENOMEM;
 
+	ret = file_read(dso, machine, cache_offset, cache->data);
+	if (ret > 0) {
 		cache->offset = cache_offset;
 		cache->size   = ret;
-	} while (0);
-
 
-	if (ret > 0) {
 		old = dso_cache__insert(dso, cache);
 		if (old) {
 			/* we lose the race */