Messages in this thread | | | Date | Thu, 20 Nov 2014 08:46:17 -0500 | From | Steven Rostedt <> | Subject | Re: [PATCH v5 2/2] tracing: add additional marks to signal very large time |
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On Thu, 20 Nov 2014 15:05:43 +0900 Namhyung Kim <namhyung@kernel.org> wrote:
> 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'. >
It is impossible if this code never changes. But we all know that wont be the case :-)
-- Steve
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