perf tests: Add 'keep tracking' test

Add a test for the newly added PERF_COUNT_SW_DUMMY event.  The test
checks that tracking events continue when an event is disabled but a
dummy software event is not disabled.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1377975053-3811-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

6 files changed, 205 insertions, 2 deletions

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index ecebfd00295e..c5dc1ad1b8d7 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -465,6 +465,7 @@ endif # NO_LIBELF
 ifndef NO_LIBUNWIND
   LIB_OBJS += $(OUTPUT)util/unwind.o
 endif
+LIB_OBJS += $(OUTPUT)tests/keep-tracking.o
 
 ifndef NO_LIBAUDIT
   BUILTIN_OBJS += $(OUTPUT)builtin-trace.o
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 8ad9415dd847..8bbeba322df9 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -108,6 +108,10 @@ static struct test {
                 .func = test__sample_parsing,
         },
         {
+                .desc = "Test using a dummy software event to keep tracking",
+                .func = test__keep_tracking,
+        },
+        {
                 .func = NULL,
         },
 };
diff --git a/tools/perf/tests/keep-tracking.c b/tools/perf/tests/keep-tracking.c
new file mode 100644
index 000000000000..d444ea2c47d9
--- /dev/null
+++ b/tools/perf/tests/keep-tracking.c
@@ -0,0 +1,154 @@
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/prctl.h>
+
+#include "parse-events.h"
+#include "evlist.h"
+#include "evsel.h"
+#include "thread_map.h"
+#include "cpumap.h"
+#include "tests.h"
+
+#define CHECK__(x) {                            \
+        while ((x) < 0) {                       \
+                pr_debug(#x " failed!\n");      \
+                goto out_err;                   \
+        }                                       \
+}
+
+#define CHECK_NOT_NULL__(x) {                   \
+        while ((x) == NULL) {                   \
+                pr_debug(#x " failed!\n");      \
+                goto out_err;                   \
+        }                                       \
+}
+
+static int find_comm(struct perf_evlist *evlist, const char *comm)
+{
+        union perf_event *event;
+        int i, found;
+
+        found = 0;
+        for (i = 0; i < evlist->nr_mmaps; i++) {
+                while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
+                        if (event->header.type == PERF_RECORD_COMM &&
+                            (pid_t)event->comm.pid == getpid() &&
+                            (pid_t)event->comm.tid == getpid() &&
+                            strcmp(event->comm.comm, comm) == 0)
+                                found += 1;
+                }
+        }
+        return found;
+}
+
+/**
+ * test__keep_tracking - test using a dummy software event to keep tracking.
+ *
+ * This function implements a test that checks that tracking events continue
+ * when an event is disabled but a dummy software event is not disabled.  If the
+ * test passes %0 is returned, otherwise %-1 is returned.
+ */
+int test__keep_tracking(void)
+{
+        struct perf_record_opts opts = {
+                .mmap_pages          = UINT_MAX,
+                .user_freq           = UINT_MAX,
+                .user_interval       = ULLONG_MAX,
+                .freq                = 4000,
+                .target              = {
+                        .uses_mmap   = true,
+                },
+        };
+        struct thread_map *threads = NULL;
+        struct cpu_map *cpus = NULL;
+        struct perf_evlist *evlist = NULL;
+        struct perf_evsel *evsel = NULL;
+        int found, err = -1;
+        const char *comm;
+
+        threads = thread_map__new(-1, getpid(), UINT_MAX);
+        CHECK_NOT_NULL__(threads);
+
+        cpus = cpu_map__new(NULL);
+        CHECK_NOT_NULL__(cpus);
+
+        evlist = perf_evlist__new();
+        CHECK_NOT_NULL__(evlist);
+
+        perf_evlist__set_maps(evlist, cpus, threads);
+
+        CHECK__(parse_events(evlist, "dummy:u"));
+        CHECK__(parse_events(evlist, "cycles:u"));
+
+        perf_evlist__config(evlist, &opts);
+
+        evsel = perf_evlist__first(evlist);
+
+        evsel->attr.comm = 1;
+        evsel->attr.disabled = 1;
+        evsel->attr.enable_on_exec = 0;
+
+        if (perf_evlist__open(evlist) < 0) {
+                fprintf(stderr, " (not supported)");
+                err = 0;
+                goto out_err;
+        }
+
+        CHECK__(perf_evlist__mmap(evlist, UINT_MAX, false));
+
+        /*
+         * First, test that a 'comm' event can be found when the event is
+         * enabled.
+         */
+
+        perf_evlist__enable(evlist);
+
+        comm = "Test COMM 1";
+        CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
+
+        perf_evlist__disable(evlist);
+
+        found = find_comm(evlist, comm);
+        if (found != 1) {
+                pr_debug("First time, failed to find tracking event.\n");
+                goto out_err;
+        }
+
+        /*
+         * Secondly, test that a 'comm' event can be found when the event is
+         * disabled with the dummy event still enabled.
+         */
+
+        perf_evlist__enable(evlist);
+
+        evsel = perf_evlist__last(evlist);
+
+        CHECK__(perf_evlist__disable_event(evlist, evsel));
+
+        comm = "Test COMM 2";
+        CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
+
+        perf_evlist__disable(evlist);
+
+        found = find_comm(evlist, comm);
+        if (found != 1) {
+                pr_debug("Seconf time, failed to find tracking event.\n");
+                goto out_err;
+        }
+
+        err = 0;
+
+out_err:
+        if (evlist) {
+                perf_evlist__disable(evlist);
+                perf_evlist__munmap(evlist);
+                perf_evlist__close(evlist);
+                perf_evlist__delete(evlist);
+        }
+        if (cpus)
+                cpu_map__delete(cpus);
+        if (threads)
+                thread_map__delete(threads);
+
+        return err;
+}
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index 83d5b71a3ce4..c048b589998a 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -38,5 +38,6 @@ int test__sw_clock_freq(void);
 int test__perf_time_to_tsc(void);
 int test__code_reading(void);
 int test__sample_parsing(void);
+int test__keep_tracking(void);
 
 #endif /* TESTS_H */
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 5df4ca91bed3..b8727ae45e3b 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -246,7 +246,7 @@ void perf_evlist__disable(struct perf_evlist *evlist)
 
         for (cpu = 0; cpu < nr_cpus; cpu++) {
                 list_for_each_entry(pos, &evlist->entries, node) {
-                        if (!perf_evsel__is_group_leader(pos))
+                        if (!perf_evsel__is_group_leader(pos) || !pos->fd)
                                 continue;
                         for (thread = 0; thread < nr_threads; thread++)
                                 ioctl(FD(pos, cpu, thread),
@@ -264,7 +264,7 @@ void perf_evlist__enable(struct perf_evlist *evlist)
 
         for (cpu = 0; cpu < nr_cpus; cpu++) {
                 list_for_each_entry(pos, &evlist->entries, node) {
-                        if (!perf_evsel__is_group_leader(pos))
+                        if (!perf_evsel__is_group_leader(pos) || !pos->fd)
                                 continue;
                         for (thread = 0; thread < nr_threads; thread++)
                                 ioctl(FD(pos, cpu, thread),
@@ -273,6 +273,44 @@ void perf_evlist__enable(struct perf_evlist *evlist)
         }
 }
 
+int perf_evlist__disable_event(struct perf_evlist *evlist,
+                               struct perf_evsel *evsel)
+{
+        int cpu, thread, err;
+
+        if (!evsel->fd)
+                return 0;
+
+        for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
+                for (thread = 0; thread < evlist->threads->nr; thread++) {
+                        err = ioctl(FD(evsel, cpu, thread),
+                                    PERF_EVENT_IOC_DISABLE, 0);
+                        if (err)
+                                return err;
+                }
+        }
+        return 0;
+}
+
+int perf_evlist__enable_event(struct perf_evlist *evlist,
+                              struct perf_evsel *evsel)
+{
+        int cpu, thread, err;
+
+        if (!evsel->fd)
+                return -EINVAL;
+
+        for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
+                for (thread = 0; thread < evlist->threads->nr; thread++) {
+                        err = ioctl(FD(evsel, cpu, thread),
+                                    PERF_EVENT_IOC_ENABLE, 0);
+                        if (err)
+                                return err;
+                }
+        }
+        return 0;
+}
+
 static int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
 {
         int nr_cpus = cpu_map__nr(evlist->cpus);
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 841a39405f6a..880d7139d2fb 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -110,6 +110,11 @@ void perf_evlist__munmap(struct perf_evlist *evlist);
 void perf_evlist__disable(struct perf_evlist *evlist);
 void perf_evlist__enable(struct perf_evlist *evlist);
 
+int perf_evlist__disable_event(struct perf_evlist *evlist,
+                               struct perf_evsel *evsel);
+int perf_evlist__enable_event(struct perf_evlist *evlist,
+                              struct perf_evsel *evsel);
+
 void perf_evlist__set_selected(struct perf_evlist *evlist,
                                struct perf_evsel *evsel);