path: root/include/linux/ftrace.h
diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2014-12-16 12:53:59 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-16 12:53:59 -0800
commita7c180aa7e76a55642e8492f28353303a50292c2 (patch)
treeb80b3575f1717a5e3a07081b5c9409805662490d /include/linux/ftrace.h
parentMerge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds (diff)
parenttracing: Add tp_printk cmdline to have tracepoints go to printk() (diff)
Merge tag 'trace-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt: "As the merge window is still open, and this code was not as complex as I thought it might be. I'm pushing this in now. This will allow Thomas to debug his irq work for 3.20. This adds two new features: 1) Allow traceopoints to be enabled right after mm_init(). By passing in the trace_event= kernel command line parameter, tracepoints can be enabled at boot up. For debugging things like the initialization of interrupts, it is needed to have tracepoints enabled very early. People have asked about this before and this has been on my todo list. As it can be helpful for Thomas to debug his upcoming 3.20 IRQ work, I'm pushing this now. This way he can add tracepoints into the IRQ set up and have users enable them when things go wrong. 2) Have the tracepoints printed via printk() (the console) when they are triggered. If the irq code locks up or reboots the box, having the tracepoint output go into the kernel ring buffer is useless for debugging. But being able to add the tp_printk kernel command line option along with the trace_event= option will have these tracepoints printed as they occur, and that can be really useful for debugging early lock up or reboot problems. This code is not that intrusive and it passed all my tests. Thomas tried them out too and it works for his needs. Link: http://lkml.kernel.org/r/20141214201609.126831471@goodmis.org" * tag 'trace-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Add tp_printk cmdline to have tracepoints go to printk() tracing: Move enabling tracepoints to just after rcu_init()
Diffstat (limited to 'include/linux/ftrace.h')
1 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index ed501953f0b2..1da602982cf9 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -39,6 +39,12 @@
+/* Main tracing buffer and events set up */
+void trace_init(void);
+static inline void trace_init(void) { }
struct module;
struct ftrace_hash;
@@ -873,6 +879,7 @@ static inline int test_tsk_trace_graph(struct task_struct *tsk)
enum ftrace_dump_mode;
extern enum ftrace_dump_mode ftrace_dump_on_oops;
+extern int tracepoint_printk;
extern void disable_trace_on_warning(void);
extern int __disable_trace_on_warning;