perf tests: Add test for caching dso file descriptors

Adding test that setup test_dso_data__fd_limit and test
dso data file descriptors are cached appropriately.

Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1401892622-30848-13-git-send-email-jolsa@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>

3 files changed, 138 insertions, 4 deletions

diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 9677a5c6a366..b8a63583566f 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -52,10 +52,14 @@ static struct test {
                 .func = test__pmu,
         },
         {
-                .desc = "Test dso data interface",
+                .desc = "Test dso data read",
                 .func = test__dso_data,
         },
         {
+                .desc = "Test dso data cache",
+                .func = test__dso_data_cache,
+        },
+        {
                 .desc = "roundtrip evsel->name check",
                 .func = test__perf_evsel__roundtrip_name_test,
         },
diff --git a/tools/perf/tests/dso-data.c b/tools/perf/tests/dso-data.c
index 738438196d9a..2d30014d716b 100644
--- a/tools/perf/tests/dso-data.c
+++ b/tools/perf/tests/dso-data.c
@@ -1,11 +1,12 @@
-#include "util.h"
-
 #include <stdlib.h>
 #include <linux/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <string.h>
-
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <api/fs/fs.h>
+#include "util.h"
 #include "machine.h"
 #include "symbol.h"
 #include "tests.h"
@@ -154,3 +155,131 @@ int test__dso_data(void)
         unlink(file);
         return 0;
 }
+
+static long open_files_cnt(void)
+{
+        char path[PATH_MAX];
+        struct dirent *dent;
+        DIR *dir;
+        long nr = 0;
+
+        scnprintf(path, PATH_MAX, "%s/self/fd", procfs__mountpoint());
+        pr_debug("fd path: %s\n", path);
+
+        dir = opendir(path);
+        TEST_ASSERT_VAL("failed to open fd directory", dir);
+
+        while ((dent = readdir(dir)) != NULL) {
+                if (!strcmp(dent->d_name, ".") ||
+                    !strcmp(dent->d_name, ".."))
+                        continue;
+
+                nr++;
+        }
+
+        closedir(dir);
+        return nr - 1;
+}
+
+static struct dso **dsos;
+
+static int dsos__create(int cnt, int size)
+{
+        int i;
+
+        dsos = malloc(sizeof(dsos) * cnt);
+        TEST_ASSERT_VAL("failed to alloc dsos array", dsos);
+
+        for (i = 0; i < cnt; i++) {
+                char *file;
+
+                file = test_file(size);
+                TEST_ASSERT_VAL("failed to get dso file", file);
+
+                dsos[i] = dso__new(file);
+                TEST_ASSERT_VAL("failed to get dso", dsos[i]);
+        }
+
+        return 0;
+}
+
+static void dsos__delete(int cnt)
+{
+        int i;
+
+        for (i = 0; i < cnt; i++) {
+                struct dso *dso = dsos[i];
+
+                unlink(dso->name);
+                dso__delete(dso);
+        }
+
+        free(dsos);
+}
+
+static int set_fd_limit(int n)
+{
+        struct rlimit rlim;
+
+        if (getrlimit(RLIMIT_NOFILE, &rlim))
+                return -1;
+
+        pr_debug("file limit %ld, new %d\n", (long) rlim.rlim_cur, n);
+
+        rlim.rlim_cur = n;
+        return setrlimit(RLIMIT_NOFILE, &rlim);
+}
+
+int test__dso_data_cache(void)
+{
+        struct machine machine;
+        long nr_end, nr = open_files_cnt();
+        int dso_cnt, limit, i, fd;
+
+        memset(&machine, 0, sizeof(machine));
+
+        /* set as system limit */
+        limit = nr * 4;
+        TEST_ASSERT_VAL("failed to set file limit", !set_fd_limit(limit));
+
+        /* and this is now our dso open FDs limit + 1 extra */
+        dso_cnt = limit / 2 + 1;
+        TEST_ASSERT_VAL("failed to create dsos\n",
+                !dsos__create(dso_cnt, TEST_FILE_SIZE));
+
+        for (i = 0; i < (dso_cnt - 1); i++) {
+                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.
+                 */
+                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;
+
+                        n = dso__data_read_offset(dso, &machine, 0, buf, BUFSIZE);
+                        TEST_ASSERT_VAL("failed to read dso", n == BUFSIZE);
+                }
+        }
+
+        /* open +1 dso over the allowed limit */
+        fd = dso__data_fd(dsos[i], &machine);
+        TEST_ASSERT_VAL("failed to get fd", fd > 0);
+
+        /* should force the first one to be closed */
+        TEST_ASSERT_VAL("failed to close dsos[0]", dsos[0]->data.fd == -1);
+
+        /* cleanup everything */
+        dsos__delete(dso_cnt);
+
+        /* Make sure we did not leak any file descriptor. */
+        nr_end = open_files_cnt();
+        pr_debug("nr start %ld, nr stop %ld\n", nr, nr_end);
+        TEST_ASSERT_VAL("failed leadking files", nr == nr_end);
+        return 0;
+}
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index 022bb68fd9c7..ccc4deb2d963 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -28,6 +28,7 @@ int test__syscall_open_tp_fields(void);
 int test__pmu(void);
 int test__attr(void);
 int test__dso_data(void);
+int test__dso_data_cache(void);
 int test__parse_events(void);
 int test__hists_link(void);
 int test__python_use(void);