@@ -50,6 +50,18 @@ config DRM_DEBUG_MM
If in doubt, say "N".
+config DRM_USE_DYNAMIC_DEBUG
+ bool "use dynamic debug to implement drm.debug"
+ default y
+ depends on DRM
+ depends on DYNAMIC_DEBUG || DYNAMIC_DEBUG_CORE
+ depends on JUMP_LABEL
+ help
+ Use dynamic-debug to avoid drm_debug_enabled() runtime overheads.
+ Due to callsite counts in DRM drivers (~4k in amdgpu) and 56
+ bytes per callsite, the .data costs can be substantial, and
+ are therefore configurable.
+
config DRM_DEBUG_SELFTEST
tristate "kselftests for DRM"
depends on DRM
@@ -3,6 +3,8 @@
# Makefile for the drm device driver. This driver provides support for the
# Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
+CFLAGS-$(CONFIG_DRM_USE_DYNAMIC_DEBUG) += -DDYNAMIC_DEBUG_MODULE
+
drm-y := drm_aperture.o drm_auth.o drm_cache.o \
drm_file.o drm_gem.o drm_ioctl.o \
drm_drv.o \
@@ -384,8 +384,14 @@ void __drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
} \
})
+#if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
#define drm_dev_dbg(dev, cat, fmt, ...) \
__drm_dev_dbg(dev, cat, fmt, ##__VA_ARGS__)
+#else
+#define drm_dev_dbg(dev, cat, fmt, ...) \
+ _dynamic_func_call_no_desc(fmt, __drm_dev_dbg, \
+ dev, cat, fmt, ##__VA_ARGS__)
+#endif
/**
* DRM_DEV_DEBUG() - Debug output for generic drm code
@@ -492,7 +498,13 @@ void ___drm_dbg(enum drm_debug_category category, const char *format, ...);
__printf(1, 2)
void __drm_err(const char *format, ...);
+#if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
#define __drm_dbg(fmt, ...) ___drm_dbg(fmt, ##__VA_ARGS__)
+#else
+#define __drm_dbg(cat, fmt, ...) \
+ _dynamic_func_call_no_desc(fmt, ___drm_dbg, \
+ cat, fmt, ##__VA_ARGS__)
+#endif
/* Macros to make printk easier */
For CONFIG_DRM_USE_DYNAMIC_DEBUG=y, wrap __drm_dbg() & __drm_dev_dbg() in one of dyndbg's Factory macros: _dynamic_func_call_no_desc(). This adds the callsite descriptor into the code, and an entry for each into /proc/dynamic_debug/control. #> echo class DRM_UT_ATOMIC +p > /proc/dynamic_debug/control CONFIG_DRM_USE_DYNAMIC_DEBUG=y/n is configurable because of the .data footprint cost of per-callsite control; 56 bytes/site * ~2k for i915, ~4k callsites for amdgpu. This is large enough that a kernel builder might not want it. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> --- drivers/gpu/drm/Kconfig | 12 ++++++++++++ drivers/gpu/drm/Makefile | 2 ++ include/drm/drm_print.h | 12 ++++++++++++ 3 files changed, 26 insertions(+)