Re: [PATCH v1] perf report: Drop cycles 0 for LBR print

From: Arnaldo Carvalho de Melo
Date: Tue Mar 28 2017 - 11:35:46 EST


Em Thu, Mar 09, 2017 at 04:06:26PM +0800, Jin Yao escreveu:
> For some platforms, for example Broadwell, it doesn't support cycles
> for LBR. But the perf always prints cycles:0, it's not necessary.
>
> The patch refactors the LBR info print code and drops the cycles:0.
>
> For example: perf report --branch-history --no-children --stdio

Can I get some reviewed-by or acked-by for this patch? Andi? Kan?

- Arnaldo

> On Broadwell:
> --0.91%--__random_r random_r.c:394 (iterations:2)
> __random_r random_r.c:360 (predicted:0.0%)
> __random_r random_r.c:380 (predicted:0.0%)
> __random_r random_r.c:357
>
> On Skylake:
> --1.07%--main div.c:39 (predicted:52.4% cycles:1 iterations:17)
> main div.c:44 (predicted:52.4% cycles:1)
> main div.c:42 (cycles:2)
> compute_flag div.c:28 (cycles:2)
> compute_flag div.c:27 (cycles:1)
> rand rand.c:28 (cycles:1)
> rand rand.c:28 (cycles:1)
> __random random.c:298 (cycles:1)
> __random random.c:297 (cycles:1)
> __random random.c:295 (cycles:1)
> __random random.c:295 (cycles:1)
> __random random.c:295 (cycles:1)
>
> Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
> ---
> tools/perf/util/callchain.c | 111 +++++++++++++++++++++++++++++---------------
> 1 file changed, 74 insertions(+), 37 deletions(-)
>
> diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
> index aba9534..f84626d 100644
> --- a/tools/perf/util/callchain.c
> +++ b/tools/perf/util/callchain.c
> @@ -1063,63 +1063,100 @@ int callchain_branch_counts(struct callchain_root *root,
> cycles_count);
> }
>
> -static int callchain_counts_printf(FILE *fp, char *bf, int bfsize,
> - u64 branch_count, u64 predicted_count,
> - u64 abort_count, u64 cycles_count,
> - u64 iter_count, u64 samples_count)
> +static int counts_str_build(char *bf, int bfsize,
> + u64 branch_count, u64 predicted_count,
> + u64 abort_count, u64 cycles_count,
> + u64 iter_count, u64 samples_count)
> {
> double predicted_percent = 0.0;
> const char *null_str = "";
> char iter_str[32];
> - char *str;
> - u64 cycles = 0;
> -
> - if (branch_count == 0) {
> - if (fp)
> - return fprintf(fp, " (calltrace)");
> + char cycle_str[32];
> + char *istr, *cstr;
> + u64 cycles;
>
> + if (branch_count == 0)
> return scnprintf(bf, bfsize, " (calltrace)");
> - }
> +
> + cycles = cycles_count / branch_count;
>
> if (iter_count && samples_count) {
> - scnprintf(iter_str, sizeof(iter_str),
> - ", iterations:%" PRId64 "",
> - iter_count / samples_count);
> - str = iter_str;
> + if (cycles > 0)
> + scnprintf(iter_str, sizeof(iter_str),
> + " iterations:%" PRId64 "",
> + iter_count / samples_count);
> + else
> + scnprintf(iter_str, sizeof(iter_str),
> + "iterations:%" PRId64 "",
> + iter_count / samples_count);
> + istr = iter_str;
> + } else
> + istr = (char *)null_str;
> +
> + if (cycles > 0) {
> + scnprintf(cycle_str, sizeof(cycle_str),
> + "cycles:%" PRId64 "", cycles);
> + cstr = cycle_str;
> } else
> - str = (char *)null_str;
> + cstr = (char *)null_str;
>
> predicted_percent = predicted_count * 100.0 / branch_count;
> - cycles = cycles_count / branch_count;
>
> - if ((predicted_percent >= 100.0) && (abort_count == 0)) {
> - if (fp)
> - return fprintf(fp, " (cycles:%" PRId64 "%s)",
> - cycles, str);
> + if ((predicted_count == branch_count) && (abort_count == 0)) {
> + if ((cycles > 0) || (istr != (char *)null_str))
> + return scnprintf(bf, bfsize, " (%s%s)", cstr, istr);
> + else
> + return scnprintf(bf, bfsize, "%s", (char *)null_str);
> + }
>
> - return scnprintf(bf, bfsize, " (cycles:%" PRId64 "%s)",
> - cycles, str);
> + if ((predicted_count < branch_count) && (abort_count == 0)) {
> + if ((cycles > 0) || (istr != (char *)null_str))
> + return scnprintf(bf, bfsize,
> + " (predicted:%.1f%% %s%s)",
> + predicted_percent, cstr, istr);
> + else {
> + return scnprintf(bf, bfsize,
> + " (predicted:%.1f%%)",
> + predicted_percent);
> + }
> }
>
> - if ((predicted_percent < 100.0) && (abort_count == 0)) {
> - if (fp)
> - return fprintf(fp,
> - " (predicted:%.1f%%, cycles:%" PRId64 "%s)",
> - predicted_percent, cycles, str);
> + if ((predicted_count == branch_count) && (abort_count > 0)) {
> + if ((cycles > 0) || (istr != (char *)null_str))
> + return scnprintf(bf, bfsize,
> + " (abort:%" PRId64 " %s%s)",
> + abort_count, cstr, istr);
> + else
> + return scnprintf(bf, bfsize,
> + " (abort:%" PRId64 ")",
> + abort_count);
> + }
>
> + if ((cycles > 0) || (istr != (char *)null_str))
> return scnprintf(bf, bfsize,
> - " (predicted:%.1f%%, cycles:%" PRId64 "%s)",
> - predicted_percent, cycles, str);
> - }
> + " (predicted:%.1f%% abort:%" PRId64 " %s%s)",
> + predicted_percent, abort_count, cstr, istr);
> +
> + return scnprintf(bf, bfsize,
> + " (predicted:%.1f%% abort:%" PRId64 ")",
> + predicted_percent, abort_count);
> +}
> +
> +static int callchain_counts_printf(FILE *fp, char *bf, int bfsize,
> + u64 branch_count, u64 predicted_count,
> + u64 abort_count, u64 cycles_count,
> + u64 iter_count, u64 samples_count)
> +{
> + char str[128];
> +
> + counts_str_build(str, sizeof(str), branch_count,
> + predicted_count, abort_count, cycles_count,
> + iter_count, samples_count);
>
> if (fp)
> - return fprintf(fp,
> - " (predicted:%.1f%%, abort:%" PRId64 ", cycles:%" PRId64 "%s)",
> - predicted_percent, abort_count, cycles, str);
> + return fprintf(fp, "%s", str);
>
> - return scnprintf(bf, bfsize,
> - " (predicted:%.1f%%, abort:%" PRId64 ", cycles:%" PRId64 "%s)",
> - predicted_percent, abort_count, cycles, str);
> + return scnprintf(bf, bfsize, "%s", str);
> }
>
> int callchain_list_counts__printf_value(struct callchain_node *node,
> --
> 2.7.4