diff options
author | Steven Rostedt <srostedt@redhat.com> | 2009-05-26 20:25:22 +0200 |
---|---|---|
committer | Frederic Weisbecker <fweisbec@gmail.com> | 2009-05-26 20:25:22 +0200 |
commit | be74b73a57645cc253d881ab0c1014eb64b9cf22 (patch) | |
tree | 83f14ae9a43fe98a1363d30d20d60245e1115382 /include/linux/ftrace_event.h | |
parent | 0e907c99391362385c8e3af2c43b904dd1fd5d73 (diff) |
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 <rostedt@goodmis.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Diffstat (limited to 'include/linux/ftrace_event.h')
-rw-r--r-- | include/linux/ftrace_event.h | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index bae51ddfabd..4b58cf1a11c 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -3,12 +3,23 @@ #include <linux/trace_seq.h> #include <linux/ring_buffer.h> - +#include <linux/percpu.h> 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: |