clock offset: print negative value in metadata

[lttng-modules.git] / lttng-events.c

diff --git a/lttng-events.c b/lttng-events.c
index f648feb67a64c8ab180c429ec77db907e2ca5f8e..e1364dd5fbd9b6692bf5055f3be07048b1c951b7 100644 (file)
--- a/lttng-events.c
+++ b/lttng-events.c
@@ -1085,17 +1085,22 @@ int lttng_session_list_tracker_pids(struct lttng_session *session)
                ret = PTR_ERR(tracker_pids_list_file);
                goto file_error;
        }
+       if (atomic_long_add_unless(&session->file->f_count,
+               1, INT_MAX) == INT_MAX) {
+               goto refcount_error;
+       }
        ret = lttng_tracker_pids_list_fops.open(NULL, tracker_pids_list_file);
        if (ret < 0)
                goto open_error;
        m = tracker_pids_list_file->private_data;
        m->private = session;
        fd_install(file_fd, tracker_pids_list_file);
-       atomic_long_inc(&session->file->f_count);
 
        return file_fd;
 
 open_error:
+       atomic_long_dec(&session->file->f_count);
+refcount_error:
        fput(tracker_pids_list_file);
 file_error:
        put_unused_fd(file_fd);
@@ -1695,6 +1700,14 @@ int _lttng_field_statedump(struct lttng_session *session,
                const struct lttng_basic_type *elem_type;
 
                elem_type = &field->type.u.array.elem_type;
+               if (field->type.u.array.elem_alignment) {
+                       ret = lttng_metadata_printf(session,
+                       "               struct { } align(%u) _%s_padding;\n",
+                                       field->type.u.array.elem_alignment * CHAR_BIT,
+                                       field->name);
+                       if (ret)
+                               return ret;
+               }
                ret = lttng_metadata_printf(session,
                        "               integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
                        elem_type->u.basic.integer.size,
@@ -1741,6 +1754,14 @@ int _lttng_field_statedump(struct lttng_session *session,
                if (ret)
                        return ret;
 
+               if (field->type.u.sequence.elem_alignment) {
+                       ret = lttng_metadata_printf(session,
+                       "               struct { } align(%u) _%s_padding;\n",
+                                       field->type.u.sequence.elem_alignment * CHAR_BIT,
+                                       field->name);
+                       if (ret)
+                               return ret;
+               }
                ret = lttng_metadata_printf(session,
                        "               integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
                        elem_type->u.basic.integer.size,
@@ -2002,11 +2023,15 @@ int _lttng_event_header_declare(struct lttng_session *session)
  * taken at start of trace.
  * Yes, this is only an approximation. Yes, we can (and will) do better
  * in future versions.
+ * Return 0 if offset is negative. It may happen if the system sets
+ * the REALTIME clock to 0 after boot.
  */
 static
-uint64_t measure_clock_offset(void)
+int64_t measure_clock_offset(void)
 {
-       uint64_t offset, monotonic[2], realtime;
+       uint64_t monotonic_avg, monotonic[2], realtime;
+       uint64_t tcf = trace_clock_freq();
+       int64_t offset;
        struct timespec rts = { 0, 0 };
        unsigned long flags;
 
@@ -2017,10 +2042,17 @@ uint64_t measure_clock_offset(void)
        monotonic[1] = trace_clock_read64();
        local_irq_restore(flags);
 
-       offset = (monotonic[0] + monotonic[1]) >> 1;
-       realtime = (uint64_t) rts.tv_sec * NSEC_PER_SEC;
-       realtime += rts.tv_nsec;
-       offset = realtime - offset;
+       monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
+       realtime = (uint64_t) rts.tv_sec * tcf;
+       if (tcf == NSEC_PER_SEC) {
+               realtime += rts.tv_nsec;
+       } else {
+               uint64_t n = rts.tv_nsec * tcf;
+
+               do_div(n, NSEC_PER_SEC);
+               realtime += n;
+       }
+       offset = (int64_t) realtime - monotonic_avg;
        return offset;
 }
 
@@ -2113,8 +2145,8 @@ int _lttng_session_metadata_statedump(struct lttng_session *session)
 
        ret = lttng_metadata_printf(session,
                "clock {\n"
-               "       name = %s;\n",
-               "monotonic"
+               "       name = \"%s\";\n",
+               trace_clock_name()
                );
        if (ret)
                goto end;
@@ -2129,13 +2161,14 @@ int _lttng_session_metadata_statedump(struct lttng_session *session)
        }
 
        ret = lttng_metadata_printf(session,
-               "       description = \"Monotonic Clock\";\n"
+               "       description = \"%s\";\n"
                "       freq = %llu; /* Frequency, in Hz */\n"
                "       /* clock value offset from Epoch is: offset * (1/freq) */\n"
-               "       offset = %llu;\n"
+               "       offset = %lld;\n"
                "};\n\n",
+               trace_clock_description(),
                (unsigned long long) trace_clock_freq(),
-               (unsigned long long) measure_clock_offset()
+               (long long) measure_clock_offset()
                );
        if (ret)
                goto end;
@@ -2143,20 +2176,23 @@ int _lttng_session_metadata_statedump(struct lttng_session *session)
        ret = lttng_metadata_printf(session,
                "typealias integer {\n"
                "       size = 27; align = 1; signed = false;\n"
-               "       map = clock.monotonic.value;\n"
+               "       map = clock.%s.value;\n"
                "} := uint27_clock_monotonic_t;\n"
                "\n"
                "typealias integer {\n"
                "       size = 32; align = %u; signed = false;\n"
-               "       map = clock.monotonic.value;\n"
+               "       map = clock.%s.value;\n"
                "} := uint32_clock_monotonic_t;\n"
                "\n"
                "typealias integer {\n"
                "       size = 64; align = %u; signed = false;\n"
-               "       map = clock.monotonic.value;\n"
+               "       map = clock.%s.value;\n"
                "} := uint64_clock_monotonic_t;\n\n",
+               trace_clock_name(),
                lttng_alignof(uint32_t) * CHAR_BIT,
-               lttng_alignof(uint64_t) * CHAR_BIT
+               trace_clock_name(),
+               lttng_alignof(uint64_t) * CHAR_BIT,
+               trace_clock_name()
                );
        if (ret)
                goto end;