From be74b73a57645cc253d881ab0c1014eb64b9cf22 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 26 May 2009 20:25:22 +0200 Subject: tracing: add __print_flags for events Developers have been asking for the ability in the ftrace event tracer to display names of bits in a flags variable. Instead of printing out c2, it would be easier to read FOO|BAR|GOO, assuming that FOO is bit 1, BAR is bit 6 and GOO is bit 7. Some examples where this would be useful are the state flags in a context switch, kmalloc flags, and even permision flags in accessing files. [ v2 changes include: Frederic Weisbecker's idea of using a mask instead of bits, thus we can output GFP_KERNEL instead of GPF_WAIT|GFP_IO|GFP_FS. Li Zefan's idea of allowing the caller of __print_flags to add their own delimiter (or no delimiter) where we can get for file permissions rwx instead of r|w|x. ] [ v3 changes: Christoph Hellwig's idea of using an array instead of va_args. ] [ Impact: better displaying of flags in trace output ] Signed-off-by: Steven Rostedt Signed-off-by: Frederic Weisbecker --- include/linux/ftrace_event.h | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'include/linux/ftrace_event.h') diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index bae51ddfabd3..4b58cf1a11c2 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -3,12 +3,23 @@ #include #include - +#include struct trace_array; struct tracer; struct dentry; +DECLARE_PER_CPU(struct trace_seq, ftrace_event_seq); + +struct trace_print_flags { + unsigned long mask; + const char *name; +}; + +const char *ftrace_print_flags_seq(struct trace_seq *p, const char *delim, + unsigned long flags, + const struct trace_print_flags *flag_array); + /* * The trace entry - the most basic unit of tracing. This is what * is printed in the end as a single line in the trace output, such as: -- cgit v1.2.3