Add include/trace/events/drm.h, with 2 new events: drm_debug() &
drm_devdbg(), and call them from drm_dbg() & drm_dev_dbg(). This is
easy, cuz the callers already build the vaf that the callee wants.
This allows the 3-5k drm.debug/on-dyndbg callsites to independently
(re-)direct messages to tracefs, not just syslog. ISTM this is good;
debug traffic can be sent (just) to the tool where it can be best
used. Over time, I'd expect to see less traffic to syslog.
NOTE: The message formats for the 2 events are both sub-optimal.
(both have event-name too)
drm_devdbg: TP_printk("cat:%d, %s %s", __entry->drm_debug_category,
"cat:%d" should be "%s", but the classnames arent really in-scope
here. Maybe the events-decl-header should be under drm somewhere,
so that class-names are available.
It would also be nice to replace the event-name with the classname,
as the names are highly client centric.
drm_dbg: TP_printk("%s", __get_str(msg))
same as above.
NB:
The existing category param in this callchain is partially redundant;
when descriptor is available, it has the callsite's class_id. If
later, CONFIG_DRM_USE_DYNAMIC_DEBUG:=y (hardwired), then category can
be dropped here, since the descriptor will always be available.
Also, if combined with header-move (or maybe its expanding inclusion
by lib/dynamic_debug), we could add the optional flags prefix, by
exposing dynamic_emit_prefix. And perhaps this could be done only in
TP_printk, to save work while writing to the ring-buffer.
Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
---
drivers/gpu/drm/drm_print.c | 25 ++++++++++++-----
include/trace/events/drm.h | 54 +++++++++++++++++++++++++++++++++++++
2 files changed, 72 insertions(+), 7 deletions(-)
create mode 100644 include/trace/events/drm.h
diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
index 92f3f45e410c..9fb0b8e40dca 100644
--- a/drivers/gpu/drm/drm_print.c
+++ b/drivers/gpu/drm/drm_print.c
@@ -35,6 +35,9 @@
#include <drm/drm_drv.h>
#include <drm/drm_print.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/drm.h>
+
/*
* __drm_debug: Enable debug output.
* Bitmask of DRM_UT_x. See include/drm/drm_print.h for details.
@@ -293,13 +296,19 @@ void __drm_dev_dbg(struct _ddebug *desc, const struct device *dev,
vaf.fmt = format;
vaf.va = &args;
- if (dev)
- dev_printk(KERN_DEBUG, dev, "[" DRM_NAME ":%ps] %pV",
- __builtin_return_address(0), &vaf);
- else
- printk(KERN_DEBUG "[" DRM_NAME ":%ps] %pV",
- __builtin_return_address(0), &vaf);
-
+ if (dev) {
+ if (desc->flags & _DPRINTK_FLAGS_PRINTK)
+ dev_printk(KERN_DEBUG, dev, "[" DRM_NAME ":%ps] %pV",
+ __builtin_return_address(0), &vaf);
+ if (desc->flags & _DPRINTK_FLAGS_TRACE)
+ trace_drm_devdbg(dev, category, &vaf);
+ } else {
+ if (desc->flags & _DPRINTK_FLAGS_PRINTK)
+ printk(KERN_DEBUG "[" DRM_NAME ":%ps] %pV",
+ __builtin_return_address(0), &vaf);
+ if (desc->flags & _DPRINTK_FLAGS_TRACE)
+ trace_drm_debug(category, &vaf);
+ }
va_end(args);
}
EXPORT_SYMBOL(__drm_dev_dbg);
@@ -319,6 +328,8 @@ void ___drm_dbg(struct _ddebug *desc, enum drm_debug_category category, const ch
printk(KERN_DEBUG "[" DRM_NAME ":%ps] %pV",
__builtin_return_address(0), &vaf);
+ trace_drm_debug(category, &vaf);
+
va_end(args);
}
EXPORT_SYMBOL(___drm_dbg);
diff --git a/include/trace/events/drm.h b/include/trace/events/drm.h
new file mode 100644
index 000000000000..589fa1e1f2c2
--- /dev/null
+++ b/include/trace/events/drm.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM drm
+
+#if !defined(_TRACE_DRM_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_DRM_H
+
+#include <linux/tracepoint.h>
+
+/* drm_debug() was called, pass its args */
+TRACE_EVENT(drm_debug,
+ TP_PROTO(int drm_debug_category, struct va_format *vaf),
+
+ TP_ARGS(drm_debug_category, vaf),
+
+ TP_STRUCT__entry(
+ __field(int, drm_debug_category)
+ __vstring(msg, vaf->fmt, vaf->va)
+ ),
+
+ TP_fast_assign(
+ __entry->drm_debug_category = drm_debug_category;
+ __assign_vstr(msg, vaf->fmt, vaf->va);
+ ),
+
+ TP_printk("%s", __get_str(msg))
+);
+
+/* drm_devdbg() was called, pass its args, preserving order */
+TRACE_EVENT(drm_devdbg,
+ TP_PROTO(const struct device *dev, int drm_debug_category, struct va_format *vaf),
+
+ TP_ARGS(dev, drm_debug_category, vaf),
+
+ TP_STRUCT__entry(
+ __field(const struct device*, dev)
+ __field(int, drm_debug_category)
+ __vstring(msg, vaf->fmt, vaf->va)
+ ),
+
+ TP_fast_assign(
+ __entry->drm_debug_category = drm_debug_category;
+ __entry->dev = dev;
+ __assign_vstr(msg, vaf->fmt, vaf->va);
+ ),
+
+ TP_printk("cat:%d, %s %s", __entry->drm_debug_category,
+ dev_name(__entry->dev), __get_str(msg))
+);
+
+#endif /* _TRACE_DRM_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
--
2.36.1
