convert ltt_nesting to a per_thread variable, and access it with volatile access

[ust.git] / libust / serialize.c

diff --git a/libust/serialize.c b/libust/serialize.c
index 011206afbe94dd7e0cdee20e9d2aae34e72627d6..4c23e8dd02451d46d6b8de34c418d40e872bc9f3 100644 (file)
--- a/libust/serialize.c
+++ b/libust/serialize.c
@@ -623,11 +623,11 @@ notrace void ltt_vtrace(const struct marker *mdata, void *probe_data,
                return;
 
        rcu_read_lock(); //ust// rcu_read_lock_sched_notrace();
-//ust//        cpu = smp_processor_id();
        cpu = ust_get_cpu();
-//ust//        __get_cpu_var(ltt_nesting)++;
-       /* FIXME: should nesting be per-cpu? */
-       ltt_nesting++;
+
+       /* Force volatile access. */
+       STORE_SHARED(ltt_nesting, LOAD_SHARED(ltt_nesting) + 1);
+       barrier();
 
        pdata = (struct ltt_active_marker *)probe_data;
        eID = mdata->event_id;
@@ -712,8 +712,10 @@ notrace void ltt_vtrace(const struct marker *mdata, void *probe_data,
                ltt_commit_slot(channel, buf, buf_offset, data_size, slot_size);
                DBG("just commited event (%s/%s) at offset %ld and size %zd", mdata->channel, mdata->name, buf_offset, slot_size);
        }
-//ust//        __get_cpu_var(ltt_nesting)--;
-       ltt_nesting--;
+
+       barrier();
+       STORE_SHARED(ltt_nesting, LOAD_SHARED(ltt_nesting) - 1);
+
        rcu_read_unlock(); //ust// rcu_read_unlock_sched_notrace();
 }