commit:HEAD~1 added pr_debug(), dev_dbg() params to the new events, but didn't actually capture the params. Do that now; add the other TP_* parts: __fields, fast-assign, and printk elements for the desccriptor and device params.
The message capture part is copied from printk:console, it gets the whole message, including dyndbg's prefixing: the dev_name() etc, the optional module:function:line decorations, and the trailing newline (which is trimmed).
dyndbg->trace-events must be enabled on both sides:
in tracefs: echo 1 > /sys/kernel/tracing/events/dyndbg/enable in dyndbg: echo module drm +T > /proc/dynamic_debug/control
This is good; it gives 2 orthogonal cuts at trace traffic, dyndbg can enable callsites indvidually, tracefs can (in principle) filter and trigger on the incoming event stream.
ATM, TP_print adds "__entry->desc->{modname,function}", which is redundant with +Tmf enabled callsites.
RFC
Perhaps the whole decorations/prefix should be excluded from the event capture ? Vincent's skip-past-KERN_DEBUG trick could be extended to skip part or all of the prefix, and leave the "decorating" of events solely to TP_printk. Whats the right separation of concerns ?
NB: __entry->desc is a pointer into kernel .data, a pretty stable reference, at least while the kernel is running.
Signed-off-by: Jim Cromie jim.cromie@gmail.com --- include/trace/events/dyndbg.h | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/include/trace/events/dyndbg.h b/include/trace/events/dyndbg.h index 82620b10e968..2ac296cb451c 100644 --- a/include/trace/events/dyndbg.h +++ b/include/trace/events/dyndbg.h @@ -14,10 +14,12 @@ TRACE_EVENT(prdbg, TP_ARGS(desc, text, len),
TP_STRUCT__entry( + __field(const struct _ddebug *, desc) __dynamic_array(char, msg, len + 1) ),
TP_fast_assign( + __entry->desc = desc; /* * Each trace entry is printed in a new line. * If the msg finishes with '\n', cut it off @@ -30,8 +32,8 @@ TRACE_EVENT(prdbg, __get_str(msg)[len] = 0; ),
- TP_printk("%s", __get_str(msg)) - + TP_printk("%s.%s %s", __entry->desc->modname, + __entry->desc->function, __get_str(msg)) );
/* capture dev_dbg() callsite descriptor, device, and message */ @@ -42,10 +44,14 @@ TRACE_EVENT(devdbg, TP_ARGS(desc, dev, text, len),
TP_STRUCT__entry( + __field(const struct _ddebug *, desc) + __field(const struct device *, dev) __dynamic_array(char, msg, len + 1) ),
TP_fast_assign( + __entry->desc = desc; + __entry->dev = (struct device *) dev; /* * Each trace entry is printed in a new line. * If the msg finishes with '\n', cut it off @@ -58,7 +64,8 @@ TRACE_EVENT(devdbg, __get_str(msg)[len] = 0; ),
- TP_printk("%s", __get_str(msg)) + TP_printk("%s.%s %s", __entry->desc->modname, + __entry->desc->function, __get_str(msg)) );
#endif /* _TRACE_DYNDBG_H */