Re: [PATCH v3 3/5] perf tools: Fix dynamic sort keys to sort properly

Arnaldo Carvalho de Melo
2016-01-06T23:06:52Z

Em Wed, Jan 06, 2016 at 09:54:59AM +0900, Namhyung Kim escreveu:
> Currently, the dynamic sort keys compares trace data using memcmp().
> But for output sorting, it should check data size and compare by word.
> Also it sorted strings in reverse order, fix it.

Can this be broken down in two patches? This is complex code, lets try
to make it as bisectable as possible.

- Arnaldo

>
> Before)
>
> $ perf report -F overhead -s prev_pid,next_pid
> ...
> # Overhead prev_pid next_pid
> # ........ .......... ..........
> #
> 0.39% 490 0
> 9.12% 225 0
> 0.04% 224 0
> 0.51% 731 189
> 0.08% 731 3
> 0.12% 731 0
> 4.82% 729 0
> 0.08% 1229 0
> 0.20% 715 0
> 4.78% 189 225
> ...
>
> After)
>
> $ perf report -F overhead -s prev_pid,next_pid
> ...
> # Overhead prev_pid next_pid
> # ........ .......... ..........
> #
> 0.43% 0 7
> 0.04% 0 11
> 0.04% 0 12
> 0.08% 0 14
> 0.04% 0 17
> 0.08% 0 19
> 0.04% 0 22
> 0.04% 0 27
> 0.04% 0 37
> 0.04% 0 42
> ...
>
> Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
> tools/perf/util/sort.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 46 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
> index 9618a64875c0..264d2b630549 100644
> --- a/tools/perf/util/sort.c
> +++ b/tools/perf/util/sort.c
> @@ -1798,6 +1798,51 @@ static int64_t __sort__hde_cmp(struct perf_hpp_fmt *fmt,
> return memcmp(a->raw_data + offset, b->raw_data + offset, size);
> }
>
> +static int64_t __sort__hde_sort(struct perf_hpp_fmt *fmt,
> + struct hist_entry *a, struct hist_entry *b)
> +{
> + struct hpp_dynamic_entry *hde;
> + struct format_field *field;
> + unsigned offset, size;
> + int64_t *a64, *b64;
> + int32_t *a32, *b32;
> + int16_t *a16, *b16;
> +
> + hde = container_of(fmt, struct hpp_dynamic_entry, hpp);
> +
> + field = hde->field;
> + if (field->flags & FIELD_IS_DYNAMIC) {
> + unsigned long long dyn;
> +
> + pevent_read_number_field(field, a->raw_data, &dyn);
> + offset = dyn & 0xffff;
> + size = (dyn >> 16) & 0xffff;
> + } else {
> + offset = field->offset;
> + size = field->size;
> + }
> +
> + if (field->flags & FIELD_IS_STRING)
> + return strcmp(b->raw_data + offset, a->raw_data + offset);
> +
> + switch (size) {
> + case 8:
> + a64 = a->raw_data + offset;
> + b64 = b->raw_data + offset;
> + return *b64 - *a64;
> + case 4:
> + a32 = a->raw_data + offset;
> + b32 = b->raw_data + offset;
> + return *b32 - *a32;
> + case 2:
> + a16 = a->raw_data + offset;
> + b16 = b->raw_data + offset;
> + return *b16 - *a16;
> + default:
> + return memcmp(b->raw_data + offset, a->raw_data + offset, size);
> + }
> +}
> +
> bool perf_hpp__is_dynamic_entry(struct perf_hpp_fmt *fmt)
> {
> return fmt->cmp == __sort__hde_cmp;
> @@ -1826,7 +1871,7 @@ __alloc_dynamic_entry(struct perf_evsel *evsel, struct format_field *field)
>
> hde->hpp.cmp = __sort__hde_cmp;
> hde->hpp.collapse = __sort__hde_cmp;
> - hde->hpp.sort = __sort__hde_cmp;
> + hde->hpp.sort = __sort__hde_sort;
>
> INIT_LIST_HEAD(&hde->hpp.list);
> INIT_LIST_HEAD(&hde->hpp.sort_list);
> --
> 2.6.4