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 | |
| 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')
| -rw-r--r-- | include/linux/ftrace_event.h | 13 | ||||
| -rw-r--r-- | include/trace/ftrace.h | 14 |
2 files changed, 26 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: diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index b5ff2e8229e..22c94719c56 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -87,6 +87,7 @@ * struct trace_seq *s = &iter->seq; * struct ftrace_raw_<call> *field; <-- defined in stage 1 * struct trace_entry *entry; + * struct trace_seq *p; * int ret; * * entry = iter->ent; @@ -98,7 +99,9 @@ * * field = (typeof(field))entry; * + * p = get_cpu_var(ftrace_event_seq); * ret = trace_seq_printf(s, <TP_printk> "\n"); + * put_cpu(); * if (!ret) * return TRACE_TYPE_PARTIAL_LINE; * @@ -119,6 +122,14 @@ #undef __get_str #define __get_str(field) ((char *)__entry + __entry->__str_loc_##field) +#undef __print_flags +#define __print_flags(flag, delim, flag_array...) \ + ({ \ + static const struct trace_print_flags flags[] = \ + { flag_array, { -1, NULL }}; \ + ftrace_print_flags_seq(p, delim, flag, flags); \ + }) + #undef TRACE_EVENT #define TRACE_EVENT(call, proto, args, tstruct, assign, print) \ enum print_line_t \ @@ -127,6 +138,7 @@ ftrace_raw_output_##call(struct trace_iterator *iter, int flags) \ struct trace_seq *s = &iter->seq; \ struct ftrace_raw_##call *field; \ struct trace_entry *entry; \ + struct trace_seq *p; \ int ret; \ \ entry = iter->ent; \ @@ -138,7 +150,9 @@ ftrace_raw_output_##call(struct trace_iterator *iter, int flags) \ \ field = (typeof(field))entry; \ \ + p = &get_cpu_var(ftrace_event_seq); \ ret = trace_seq_printf(s, #call ": " print); \ + put_cpu(); \ if (!ret) \ return TRACE_TYPE_PARTIAL_LINE; \ \ |