Messages in this thread | | | From | Namhyung Kim <> | Subject | Re: [PATCH v5 2/2] tracing: add additional marks to signal very large time | Date | Thu, 20 Nov 2014 15:05:43 +0900 |
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Hi Steve and Byungchul,
On Wed, 19 Nov 2014 20:06:04 -0500, Steven Rostedt wrote: > On Thu, 20 Nov 2014 09:15:35 +0900 > byungchul.park@lge.com wrote: >> -static unsigned long preempt_mark_thresh_us = 100; >> +#undef MARK >> +#define MARK(v, s) {.val = v, .sym = s} >> +/* trace overhead mark */ >> +static const struct trace_mark { >> + unsigned long long val; /* unit: nsec */ >> + char sym; >> +} mark[] = { >> + MARK(1000000000ULL , '$'), /* 1 sec */ >> + MARK(1000000ULL , '#'), /* 1000 usecs */ >> + MARK(100000ULL , '!'), /* 100 usecs */ >> + MARK(10000ULL , '+'), /* 10 usecs */ >> + MARK(0ULL , ' '), /* 0 usecs */ >> +}; >> +#undef MARK >> + >> +char trace_find_mark(unsigned long long d) >> +{ >> + int i; >> + int size = ARRAY_SIZE(mark); >> + >> + for (i = 0; i < size; i++) { >> + if (d >= mark[i].val) >> + break; >> + } >> + >> + return (i == size)? ' ' : mark[i].sym; > > Change this to: > > /* The break from loop must have been hit */ > if (WARN_ON_ONCE(i == size)) > return ' ';
I think it's impossible since it's always true that 'd >= 0'.
Thanks, Namhyung
> > return mark[i].sym; > > -- Steve > > >> +} >> >> static int >> lat_print_timestamp(struct trace_iterator *iter, u64 next_ts) >> @@ -506,8 +532,7 @@ lat_print_timestamp(struct trace_iterator *iter, u64 next_ts) >> return trace_seq_printf( >> s, " %4lldus%c: ", >> abs_ts, >> - rel_ts > preempt_mark_thresh_us ? '!' : >> - rel_ts > 1 ? '+' : ' '); >> + trace_find_mark(rel_ts * NSEC_PER_USEC)); >> } else { /* !verbose && !in_ns */ >> return trace_seq_printf(s, " %4lld: ", abs_ts); >> } >> @@ -692,7 +717,7 @@ int register_ftrace_event(struct trace_event *event) >> goto out; >> >> } else { >> - >> + >> event->type = next_event_type++; >> list = &ftrace_event_list; >> }
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