s390/debug: avoid function call for debug_sprintf_*
debug_sprintf_event/exception are called even for debug events
with a disabling debug level. All other functions already do
the check in a wrapper function. Lets do the same here.
Due to the var_args the compiler rejects to make this function
inline. So let's wrap this via a macro.
This patch saves around 80 ns on my z196 for a KVM round trip (we
have two debug statements for entry and exit) when KVM is build as
a module.
The savings for built-in drivers is smaller as we then avoid the
PLT overhead for a function call.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/debug.h b/arch/s390/include/asm/debug.h
index 530c15e..0206c80 100644
--- a/arch/s390/include/asm/debug.h
+++ b/arch/s390/include/asm/debug.h
@@ -151,9 +151,21 @@
* stored in the s390dbf. See Documentation/s390/s390dbf.txt for more details!
*/
extern debug_entry_t *
-debug_sprintf_event(debug_info_t* id,int level,char *string,...)
+__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
__attribute__ ((format(printf, 3, 4)));
+#define debug_sprintf_event(_id, _level, _fmt, ...) \
+({ \
+ debug_entry_t *__ret; \
+ debug_info_t *__id = _id; \
+ int __level = _level; \
+ if ((!__id) || (__level > __id->level)) \
+ __ret = NULL; \
+ else \
+ __ret = __debug_sprintf_event(__id, __level, \
+ _fmt, ## __VA_ARGS__); \
+ __ret; \
+})
static inline debug_entry_t*
debug_exception(debug_info_t* id, int level, void* data, int length)
@@ -194,9 +206,22 @@
* stored in the s390dbf. See Documentation/s390/s390dbf.txt for more details!
*/
extern debug_entry_t *
-debug_sprintf_exception(debug_info_t* id,int level,char *string,...)
+__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
__attribute__ ((format(printf, 3, 4)));
+#define debug_sprintf_exception(_id, _level, _fmt, ...) \
+({ \
+ debug_entry_t *__ret; \
+ debug_info_t *__id = _id; \
+ int __level = _level; \
+ if ((!__id) || (__level > __id->level)) \
+ __ret = NULL; \
+ else \
+ __ret = __debug_sprintf_exception(__id, __level, \
+ _fmt, ## __VA_ARGS__);\
+ __ret; \
+})
+
int debug_register_view(debug_info_t* id, struct debug_view* view);
int debug_unregister_view(debug_info_t* id, struct debug_view* view);
diff --git a/arch/s390/kernel/debug.c b/arch/s390/kernel/debug.c
index ee8390d..c1f21ac 100644
--- a/arch/s390/kernel/debug.c
+++ b/arch/s390/kernel/debug.c
@@ -1019,7 +1019,7 @@
*/
debug_entry_t*
-debug_sprintf_event(debug_info_t* id, int level,char *string,...)
+__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
{
va_list ap;
int numargs,idx;
@@ -1027,8 +1027,6 @@
debug_sprintf_entry_t *curr_event;
debug_entry_t *active;
- if((!id) || (level > id->level))
- return NULL;
if (!debug_active || !id->areas)
return NULL;
numargs=debug_count_numargs(string);
@@ -1050,14 +1048,14 @@
return active;
}
-EXPORT_SYMBOL(debug_sprintf_event);
+EXPORT_SYMBOL(__debug_sprintf_event);
/*
* debug_sprintf_exception:
*/
debug_entry_t*
-debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
+__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
{
va_list ap;
int numargs,idx;
@@ -1065,8 +1063,6 @@
debug_sprintf_entry_t *curr_event;
debug_entry_t *active;
- if((!id) || (level > id->level))
- return NULL;
if (!debug_active || !id->areas)
return NULL;
@@ -1089,7 +1085,7 @@
return active;
}
-EXPORT_SYMBOL(debug_sprintf_exception);
+EXPORT_SYMBOL(__debug_sprintf_exception);
/*
* debug_register_view: