Hello,
On Thu, Nov 13, 2014 at 10:32:06PM -0500, Steven Rostedt wrote:
> On Wed, 5 Nov 2014 16:18:45 +0900
> byungchul.p...@lge.com wrote:
>
> > +/* trace overhead mark */
> > +struct trace_mark {
> > + unsigned long long val; /* unit: nsec */
> > + char sym;
> > +};
>
> Please format the above to:
>
> struct trace_mark {
> unsigned long long val;
> char sym;
> };
Thank you, I will do it.
>
> > +
> > +#define DEFINE_MARK_STRUCT static const struct trace_mark mark[]
>
> Why is this a macro?
Because I want to hide the 'mark' variable so that user dont need to know it.
If this macro wouldn't be used, the function or macro to find and get a symbol
must know what the variable is. And I didnt want to take an additional arg
'mark' to the function or macro.
I will explicitly define the variable 'mark' in the c file and use it in
the function to find and get a corresponding symbol, if it would be ok.
>
> > +#define DEFINE_MARK(v, s) {.val = v, .sym = s}
> > +#define MARK(d) \
> > +({ \
> > + int i = ARRAY_SIZE(mark); \
> > + while ((unsigned long long)(d) <= mark[--i].val && i > 0); \
> > + mark[i].sym; \
> > +})
>
> Why is this a macro and not a static inline?
I wanted to couple static data 'mark' and macro 'MARK' only in .h and
abstract its details. But I will move it to .c explicitly if it looks better.
>
> static inline char find_trace_mark(unsigned long long duration)
> {
> int i = ARRAY_SIZE(mark);
>
> while (duration <= mark[--i].val && i > 0)
> ;
>
> return make[i]. sym;
> }
>
> That's much more readable.
>
> >
> > /**
> > * struct tracer - a specific tracer and its callbacks to interact with
> > debugfs
> > diff --git a/kernel/trace/trace_functions_graph.c
> > b/kernel/trace/trace_functions_graph.c
> > index cb33f46..8a62907 100644
> > --- a/kernel/trace/trace_functions_graph.c
> > +++ b/kernel/trace/trace_functions_graph.c
> > @@ -797,6 +797,14 @@ trace_print_graph_duration(unsigned long long
> > duration, struct trace_seq *s)
> > return TRACE_TYPE_HANDLED;
> > }
> >
> > +DEFINE_MARK_STRUCT = {
> > + DEFINE_MARK(0ULL , ' '), /* 0 usecs */
> > + DEFINE_MARK(10000ULL , '+'), /* 10 usecs */
> > + DEFINE_MARK(100000ULL , '!'), /* 100 usecs */
> > + DEFINE_MARK(1000000ULL , '#'), /* 1000 usecs */
> > + DEFINE_MARK(1000000000ULL , '$'), /* 1 sec */
> > +};
>
> Don't need to use a name as big as DEFINE_MARK. Just have:
>
> #undef MARK
> #define MARK(v, s) { .val = v, .sym = s }
>
Thank you, I will do it.
> struct trace_mark mark[] = {
> MARK(0ULL , ' '), /* 0 usecs */
> [...]
> };
>
> With the define directly above the call, we don't need need to be that
> descriptive.
>
I still wonder if it's better to define 'mark' explicitly in .c. Anyway
I'll fix it. :)
> > +
> > static enum print_line_t
> > print_graph_duration(unsigned long long duration, struct trace_seq *s,
> > u32 flags)
> > @@ -822,12 +830,7 @@ print_graph_duration(unsigned long long duration,
> > struct trace_seq *s,
> >
> > /* Signal a overhead of time execution to the output */
> > if (flags & TRACE_GRAPH_PRINT_OVERHEAD) {
> > - /* Duration exceeded 100 usecs */
> > - if (duration > 100000ULL)
> > - ret = trace_seq_puts(s, "! ");
> > - /* Duration exceeded 10 usecs */
> > - else if (duration > 10000ULL)
> > - ret = trace_seq_puts(s, "+ ");
> > + ret = trace_seq_printf(s, "%c ", MARK(duration));
>
> Then this could just be:
>
> ret = trace_seq_printf(s, "%c ",
> find_trace_mark(duration));
>
Thank you very much for your kindness!
> -- Steve
>
> > }
> >
> > /*
>
> --
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