Changeset ba0e9631 in rtems

Timestamp:

Aug 10, 2018, 5:34:03 AM (2 years ago)

Author:

Sebastian Huber <sebastian.huber@…>

Branches:

5, master

Children:

6695d02

Parents:

a36aa86

git-author:

Sebastian Huber <sebastian.huber@…> (08/10/18 05:34:03)

git-committer:

Sebastian Huber <sebastian.huber@…> (08/23/18 12:38:41)

Message:

score: Do not inline _Thread_Dispatch_enable()

This function is slighly too complex for inlining with two if
statements. The caller already needs a stack frame due to the potential
call to _Thread_Do_dispatch(). In _Thread_Dispatch_enable() the call to
_Thread_Do_dispatch() can be optimized to a tail call.

A text size comparision

(text size after patch - text size before patch)

/ text size before patch

on sparc/erc32 with SMP enabled showed these results:

Minimum -0.000697892 (fsdosfsname01.exe)
Median -0.00745021 (psxtimes01.exe)
Maximum -0.0233032 (spscheduler01.exe)

A text size comparision

text size after patch - text size before patch

on sparc/erc32 with SMP enabled showed these results:

Minimum -3312 (ada_sp09.exe)
Median -1024 (tm15.exe)
Maximum -592 (spglobalcon01.exe)

Location:

cpukit

Files:

• include/rtems/score/threaddispatch.h (modified) (1 diff)
• score/src/threaddispatch.c (modified) (1 diff)

cpukit/include/rtems/score/threaddispatch.h

@@ -206 +206 @@
  * @brief Enables thread dispatching.
  *
- * May perfrom a thread dispatch if necessary as a side-effect.
- *
- * @param[in] cpu_self The current processor.
- */
-RTEMS_INLINE_ROUTINE void _Thread_Dispatch_enable( Per_CPU_Control *cpu_self )
-{
-  uint32_t disable_level = cpu_self->thread_dispatch_disable_level;
-
-  if ( disable_level == 1 ) {
-    ISR_Level level;
-
-    _ISR_Local_disable( level );
-
-    if (
-      cpu_self->dispatch_necessary
-#if defined(RTEMS_SCORE_ROBUST_THREAD_DISPATCH)
-        || !_ISR_Is_enabled( level )
-#endif
-    ) {
-      _Thread_Do_dispatch( cpu_self, level );
-    } else {
-      cpu_self->thread_dispatch_disable_level = 0;
-      _Profiling_Thread_dispatch_enable( cpu_self, 0 );
-      _ISR_Local_enable( level );
-    }
-  } else {
-    _Assert( disable_level > 0 );
-    cpu_self->thread_dispatch_disable_level = disable_level - 1;
-  }
-}
+ * May perform a thread dispatch if necessary as a side-effect.
+ *
+ * @param[in] cpu_self The current processor.
+ */
+void _Thread_Dispatch_enable( Per_CPU_Control *cpu_self );
 
 /**

cpukit/score/src/threaddispatch.c

@@ -268 +268 @@
   _Thread_Do_dispatch( cpu_self, level );
 }
+
+void _Thread_Dispatch_enable( Per_CPU_Control *cpu_self )
+{
+  uint32_t disable_level = cpu_self->thread_dispatch_disable_level;
+
+  if ( disable_level == 1 ) {
+    ISR_Level level;
+
+    _ISR_Local_disable( level );
+
+    if (
+      cpu_self->dispatch_necessary
+#if defined(RTEMS_SCORE_ROBUST_THREAD_DISPATCH)
+        || !_ISR_Is_enabled( level )
+#endif
+    ) {
+      _Thread_Do_dispatch( cpu_self, level );
+    } else {
+      cpu_self->thread_dispatch_disable_level = 0;
+      _Profiling_Thread_dispatch_enable( cpu_self, 0 );
+      _ISR_Local_enable( level );
+    }
+  } else {
+    _Assert( disable_level > 0 );
+    cpu_self->thread_dispatch_disable_level = disable_level - 1;
+  }
+}