Add packet tracing hint

This avoids checking the buffer flags bit if tracing is not enabled.

Change-Id: I32e1a90b5fd10318254c611344488bc2a441c71e
Signed-off-by: Todd Foggoa (tfoggoa) <tfoggoa@cisco.com>

2 files changed, 7 insertions, 0 deletions

diff --git a/vlib/vlib/trace.c b/vlib/vlib/trace.c
index b3008644..4a611ee9 100644
--- a/vlib/vlib/trace.c
+++ b/vlib/vlib/trace.c
@@ -121,6 +121,8 @@ clear_trace_buffer (void)
     tm = &this_vlib_main->trace_main;
     mainheap = clib_mem_set_heap (this_vlib_main->heap_base);
 
+    tm->trace_active_hint = 0;
+
     for (i = 0; i < vec_len (tm->trace_buffer_pool); i++)
       if (! pool_is_free_index (tm->trace_buffer_pool, i))
         vec_free (tm->trace_buffer_pool[i]);
@@ -369,6 +371,8 @@ cli_add_trace_buffer (vlib_main_t * vm,
     void *oldheap;
     tm = &this_vlib_main->trace_main;
 
+    tm->trace_active_hint = 1;
+
     oldheap = clib_mem_set_heap (this_vlib_main->heap_base);
 
     vec_validate (tm->nodes, node_index);
diff --git a/vlib/vlib/trace.h b/vlib/vlib/trace.h
index 50e51638..fe5d7377 100644
--- a/vlib/vlib/trace.h
+++ b/vlib/vlib/trace.h
@@ -76,6 +76,9 @@ typedef struct {
 #define FILTER_FLAG_EXCLUDE 2
   u32 filter_count;
 
+  /* set on trace add, cleared on clear trace */
+  u32 trace_active_hint;
+
   /* Per node trace counts. */
   vlib_trace_node_t * nodes;
 } vlib_trace_main_t;