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

Namhyung Kim
2016-01-06T23:27:48Z

On Wed, Jan 06, 2016 at 08:06:43PM -0300, Arnaldo Carvalho de Melo wrote:
> 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.

OK, I'll break out the string part then. But I think it doesn't help
much to reduce the complexity.

Thanks,
Namhyung

>
> - 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