Duplicate drm_debug_enabled() code into both "basic" and "dyndbg" ifdef branches. Then add a pr_debug("todo: ...") into the "dyndbg" branch.
Then convert the "dyndbg" branch's code to a macro, so that the pr_debug() get its callsite info from the invoking function, instead of from drm_debug_enabled() itself.
This gives us unique callsite info for the 8 remaining users of drm_debug_enabled(), and lets us enable them individually to see how much logging traffic they generate. The oft-visited callsites can then be reviewed for runtime cost and possible optimizations.
Heres what we get:
bash-5.1# modprobe drm dyndbg: 384 debug prints in module drm bash-5.1# grep todo: /proc/dynamic_debug/control drivers/gpu/drm/drm_edid.c:1843 [drm]connector_bad_edid =_ "todo: maybe avoid via dyndbg\012" drivers/gpu/drm/drm_print.c:309 [drm]___drm_dbg =p "todo: maybe avoid via dyndbg\012" drivers/gpu/drm/drm_print.c:286 [drm]__drm_dev_dbg =p "todo: maybe avoid via dyndbg\012" drivers/gpu/drm/drm_vblank.c:1491 [drm]drm_vblank_restore =_ "todo: maybe avoid via dyndbg\012" drivers/gpu/drm/drm_vblank.c:787 [drm]drm_crtc_vblank_helper_get_vblank_timestamp_internal =_ "todo: maybe avoid via dyndbg\012" drivers/gpu/drm/drm_vblank.c:410 [drm]drm_crtc_accurate_vblank_count =_ "todo: maybe avoid via dyndbg\012" drivers/gpu/drm/drm_atomic_uapi.c:1457 [drm]drm_mode_atomic_ioctl =_ "todo: maybe avoid via dyndbg\012" drivers/gpu/drm/drm_edid_load.c:178 [drm]edid_load =_ "todo: maybe avoid via dyndbg\012"
At quick glance, edid won't qualify, drm_print might, drm_vblank is strongest chance, maybe atomic-ioctl too.
Signed-off-by: Jim Cromie jim.cromie@gmail.com --- include/drm/drm_print.h | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h index 392cff7cb95c..a902bd4d8c55 100644 --- a/include/drm/drm_print.h +++ b/include/drm/drm_print.h @@ -381,6 +381,11 @@ enum drm_debug_category { #define DRM_DBG_CAT_DP DRM_UT_DP #define DRM_DBG_CAT_DRMRES DRM_UT_DRMRES
+static inline bool drm_debug_enabled(enum drm_debug_category category) +{ + return unlikely(__drm_debug & category); +} + #else /* CONFIG_DRM_USE_DYNAMIC_DEBUG */
/* join prefix + format in cpp so dyndbg can see it */ @@ -414,12 +419,13 @@ enum drm_debug_category { #define DRM_DBG_CAT_DP "drm:dp: " #define DRM_DBG_CAT_DRMRES "drm:res: "
-#endif /* CONFIG_DRM_USE_DYNAMIC_DEBUG */ +#define drm_debug_enabled(category) \ + ({ \ + pr_debug("todo: maybe avoid via dyndbg\n"); \ + unlikely(__drm_debug & (category)); \ + })
-static inline bool drm_debug_enabled(enum drm_debug_category category) -{ - return unlikely(__drm_debug & category); -} +#endif /* CONFIG_DRM_USE_DYNAMIC_DEBUG */
/* * struct device based logging @@ -582,7 +588,6 @@ void __drm_dev_dbg(const struct device *dev, enum drm_debug_category category, #define drm_dbg_drmres(drm, fmt, ...) \ drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_DBG_CAT_DRMRES, fmt, ##__VA_ARGS__)
- /* * printk based logging *