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 makes the (~4000) callsites controllable, typically by class:
# 0 is DRM_UT_CORE #> echo module drm class 0 +p > /proc/dynamic_debug/control
=N: keeps direct forwarding: drm_*_dbg -> __drm_*_dbg()
I added the CONFIG_DRM_USE_DYNAMIC_DEBUG item because of the .data footprint cost of per-callsite control; 56 bytes/site * ~2k,4k callsites (for i915, amdgpu), which is significant enough that a user might not want it. Using CONFIG_DYNAMIC_DEBUG_CORE only eliminates the builtin portion, leaving only drm modules, but still 200k of module data is a lot.
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(+)
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index b1f22e457fd0..ec14a1cd4449 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -63,6 +63,18 @@ 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 diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 301a44dc18e3..24e6410d6c0e 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -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 \ diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h index 4bed99326631..06f0ee06be1f 100644 --- a/include/drm/drm_print.h +++ b/include/drm/drm_print.h @@ -383,8 +383,14 @@ 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 @@ -491,7 +497,13 @@ 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 */