summaryrefslogtreecommitdiffstats
path: root/kernel/trace/trace_output.h
diff options
context:
space:
mode:
authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>2013-03-08 21:02:34 -0500
committerSteven Rostedt <rostedt@goodmis.org>2013-03-15 00:35:55 -0400
commit09ae72348eccb60e304cf8ce94653f4a78fcd407 (patch)
tree28c48644f71df4752556d9f5b15efb889e57af56 /kernel/trace/trace_output.h
parent153e8ed913b022d2003866a848af9fadc041403f (diff)
downloadop-kernel-dev-09ae72348eccb60e304cf8ce94653f4a78fcd407.zip
op-kernel-dev-09ae72348eccb60e304cf8ce94653f4a78fcd407.tar.gz
tracing: Add trace_puts() for even faster trace_printk() tracing
The trace_printk() is extremely fast and is very handy as it can be used in any context (including NMIs!). But it still requires scanning the fmt string for parsing the args. Even the trace_bprintk() requires a scan to know what args will be saved, although it doesn't copy the format string itself. Several times trace_printk() has no args, and wastes cpu cycles scanning the fmt string. Adding trace_puts() allows the developer to use an even faster tracing method that only saves the pointer to the string in the ring buffer without doing any format parsing at all. This will help remove even more of the "Heisenbug" effect, when debugging. Also fixed up the F_printk()s for the ftrace internal bprint and print events. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_output.h')
-rw-r--r--kernel/trace/trace_output.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h
index c038eba..af77870 100644
--- a/kernel/trace/trace_output.h
+++ b/kernel/trace/trace_output.h
@@ -5,6 +5,8 @@
#include "trace.h"
extern enum print_line_t
+trace_print_bputs_msg_only(struct trace_iterator *iter);
+extern enum print_line_t
trace_print_bprintk_msg_only(struct trace_iterator *iter);
extern enum print_line_t
trace_print_printk_msg_only(struct trace_iterator *iter);
OpenPOWER on IntegriCloud