drm: Pull the test on drm_debug in the logging macros
In the logging code, we are currently checking is we need to output in
drm_ut_debug_printk(). This is too late. The problem is that when we write
something like:
DRM_DEBUG_DRIVER("ELD on [CONNECTOR:%d:%s], [ENCODER:%d:%s]\n",
connector->base.id,
drm_get_connector_name(connector),
connector->encoder->base.id,
drm_get_encoder_name(connector->encoder));
We start by evaluating the arguments (so call drm_get_connector_name() and
drm_get_connector_name()) before ending up in drm_ut_debug_printk() which will
then does nothing.
This means we execute a lot of instructions (drm_get_connector_name(), in turn,
calls snprintf() for example) to happily discard them in the normal case,
drm.debug=0.
So, let's put the test on drm_debug earlier, in the macros themselves.
Sprinkle an unlikely() as well for good measure.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 665176e..cde1562 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -121,9 +121,8 @@
#define DRM_UT_KMS 0x04
#define DRM_UT_PRIME 0x08
-extern __printf(4, 5)
-void drm_ut_debug_printk(unsigned int request_level,
- const char *prefix,
+extern __printf(3, 4)
+void drm_ut_debug_printk(const char *prefix,
const char *function_name,
const char *format, ...);
extern __printf(2, 3)
@@ -209,24 +208,28 @@
#if DRM_DEBUG_CODE
#define DRM_DEBUG(fmt, args...) \
do { \
- drm_ut_debug_printk(DRM_UT_CORE, DRM_NAME, \
- __func__, fmt, ##args); \
+ if (unlikely(drm_debug & DRM_UT_CORE)) \
+ drm_ut_debug_printk(DRM_NAME, __func__, \
+ fmt, ##args); \
} while (0)
#define DRM_DEBUG_DRIVER(fmt, args...) \
do { \
- drm_ut_debug_printk(DRM_UT_DRIVER, DRM_NAME, \
- __func__, fmt, ##args); \
+ if (unlikely(drm_debug & DRM_UT_DRIVER)) \
+ drm_ut_debug_printk(DRM_NAME, __func__, \
+ fmt, ##args); \
} while (0)
-#define DRM_DEBUG_KMS(fmt, args...) \
+#define DRM_DEBUG_KMS(fmt, args...) \
do { \
- drm_ut_debug_printk(DRM_UT_KMS, DRM_NAME, \
- __func__, fmt, ##args); \
+ if (unlikely(drm_debug & DRM_UT_KMS)) \
+ drm_ut_debug_printk(DRM_NAME, __func__, \
+ fmt, ##args); \
} while (0)
#define DRM_DEBUG_PRIME(fmt, args...) \
do { \
- drm_ut_debug_printk(DRM_UT_PRIME, DRM_NAME, \
- __func__, fmt, ##args); \
+ if (unlikely(drm_debug & DRM_UT_PRIME)) \
+ drm_ut_debug_printk(DRM_NAME, __func__, \
+ fmt, ##args); \
} while (0)
#else
#define DRM_DEBUG_DRIVER(fmt, args...) do { } while (0)