Add support for kvm x86 specific tracepoints

[lttng-modules.git] / lttng-context-vppid.c

diff --git a/lttng-context-vppid.c b/lttng-context-vppid.c
index 365d97394e89c98094b43dacc5918ee353271c00..e36b55523feae1df2344001e1711a29613823b83 100644 (file)
--- a/lttng-context-vppid.c
+++ b/lttng-context-vppid.c
@@ -51,6 +51,15 @@ void vppid_record(struct lttng_ctx_field *field,
         * current nsproxy can be NULL when scheduled out of exit. pid_vnr uses
         * the current thread nsproxy to perform the lookup.
         */
+
+       /*
+        * TODO: when we eventually add RCU subsystem instrumentation,
+        * taking the rcu read lock here will trigger RCU tracing
+        * recursively. We should modify the kernel synchronization so
+        * it synchronizes both for RCU and RCU sched, and rely on
+        * rcu_read_lock_sched_notrace.
+        */
+
        rcu_read_lock();
        parent = rcu_dereference(current->real_parent);
        if (!current->nsproxy)
@@ -77,7 +86,7 @@ int lttng_add_vppid_to_ctx(struct lttng_ctx **ctx)
        field->event_field.type.atype = atype_integer;
        field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT;
        field->event_field.type.u.basic.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT;
-       field->event_field.type.u.basic.integer.signedness = is_signed_type(pid_t);
+       field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(pid_t);
        field->event_field.type.u.basic.integer.reverse_byte_order = 0;
        field->event_field.type.u.basic.integer.base = 10;
        field->event_field.type.u.basic.integer.encoding = lttng_encode_none;