* Fixed my fix for make_space() wrapping. It's always a good idea to

write code aligned to what one has written in the comment (or the
  other way around).
* Made trace_entry structure doubly linked, by introducing a
  previous_size member. By using bit fields, shrinking the flags field
  to 4 bits, and not saving the lower two bits of size and previous_size
  (which are always 0 due to alignment), the structure remains 4 byte
  sized and can still address the same entry size.
* kBufferSize is no longer one less than it could be.
* "traced" command:
  - Use static variable for the iteration state rather then cluttering
    the temporary debug variable name space.
  - The <count> parameter can now be negative, in which case the entries
    before (and including) <start> are printed.
  - Added a new optional parameter, specifying the maximal number of
    entries to be filtered. Filtered iteration is beautifully
    comfortable now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23678 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/tracing.h

@@ -11,8 +11,9 @@
 
 
 struct trace_entry {
-	uint16  size;
-	uint16  flags;
+	uint32	size			: 14;		// actual size is *4
+	uint32	previous_size	: 14;		// actual size is *4
+	uint32	flags			: 4;
 };
 
 #ifdef __cplusplus
@@ -37,7 +38,7 @@ class TraceOutput {
 		size_t	fSize;
 };
 
-class TraceEntry : trace_entry {
+class TraceEntry : public trace_entry {
 	public:
 		TraceEntry();
 		virtual ~TraceEntry();