Do not rely on dso__data_read_offset() will always call dso__data_fd()
internally. With multi-thread support, accessing a fd will be
protected by a lock and it'll cause a huge contention. It can be
avoided since we can skip reading from file if there's a data in the
dso cache.
If one needs to call the dso__data_read_offset(), [s]he also needs to
call dso__data_fd() (or set dso->binary_type at least) first like the
dwarf unwind code does.
Signed-off-by: Namhyung Kim <namhy...@kernel.org>
---
tools/perf/tests/dso-data.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/tools/perf/tests/dso-data.c b/tools/perf/tests/dso-data.c
index 22a8c428283a..513e5febbe5a 100644
--- a/tools/perf/tests/dso-data.c
+++ b/tools/perf/tests/dso-data.c
@@ -112,6 +112,9 @@ int test__dso_data(void)
dso = dso__new((const char *)file);
+ TEST_ASSERT_VAL("Failed to access to dso",
+ dso__data_fd(dso, &machine) >= 0);
+
/* Basic 10 bytes tests. */
for (i = 0; i < ARRAY_SIZE(offsets); i++) {
struct test_data_offset *data = &offsets[i];
@@ -252,13 +255,13 @@ int test__dso_data_cache(void)
struct dso *dso = dsos[i];
/*
- * Open dsos via dso__data_fd or dso__data_read_offset.
- * Both opens the data file and keep it open.
+ * Open dsos via dso__data_fd(), it opens the data
+ * file and keep it open (unless open file limit).
*/
+ fd = dso__data_fd(dso, &machine);
+ TEST_ASSERT_VAL("failed to get fd", fd > 0);
+
if (i % 2) {
- fd = dso__data_fd(dso, &machine);
- TEST_ASSERT_VAL("failed to get fd", fd > 0);
- } else {
#define BUFSIZE 10
u8 buf[BUFSIZE];
ssize_t n;
--
2.2.2
--
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