[PATCH v4 30/58] dyndbg: reserve flag-bit _DPRINTK_FLAGS_PREFIX_CACHED

[Jim Cromie]

Reserve a flag-bit to remember that a pr-debug callsite is/was:
- enabled, with +p
- wants a dynamic-prefix, with 1+ of module:function:sourcefile
- was previously called
- was thus saved in the prefix cache. NOT YET.

This allows (later) to cache part/all of the dynamic-prefix for each
pr_debug that gets called.

The cache contents must avoid the Thread-id (its not callsite), and
could avoid the line (to shrink the cache).  But then line needs %d
each time pr_debug is reached.

ATM, this is just the flag-bit reservation.

Signed-off-by: Jim Cromie <jim.cromie at gmail.com>
---
 include/linux/dynamic_debug.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index bc26bc9128c1c..0f7476456614e 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -38,6 +38,7 @@ struct _ddebug {
 #define _DPRINTK_FLAGS_INCL_LINENO	(1<<3)
 #define _DPRINTK_FLAGS_INCL_TID		(1<<4)
 #define _DPRINTK_FLAGS_INCL_SOURCENAME	(1<<5)
+#define _DPRINTK_FLAGS_PREFIX_CACHED	(1<<7)
 
 #define _DPRINTK_FLAGS_INCL_ANY		\
 	(_DPRINTK_FLAGS_INCL_MODNAME | _DPRINTK_FLAGS_INCL_FUNCNAME |\
-- 
2.50.1