drm_print: wrap drm_*_dbg in dyndbg descriptor factory macro

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>
Link: https://lore.kernel.org/r/20220912052852.1123868-5-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jim Cromie 2022-09-11 23:28:47 -06:00 committed by Greg Kroah-Hartman
parent e820f52577
commit 84ec67288c
3 changed files with 26 additions and 0 deletions

View file

@ -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

View file

@ -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 \

View file

@ -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 */