lkml.org 
[lkml]   [2015]   [Feb]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 02/21] perf tests: Do not rely on dso__data_read_offset() to open dso
Date
From: Namhyung Kim <namhyung@kernel.org>

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 <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1422585209-32742-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
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;
--
1.9.3


\
 
 \ /
  Last update: 2015-02-11 22:21    [W:0.117 / U:23.812 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site