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

Arnaldo Carvalho de Melo
2016-01-06T23:31:57Z

Em Thu, Jan 07, 2016 at 08:26:45AM +0900, Namhyung Kim escreveu:
> 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.

Well, number of patches is not a problem, everytime I see a "Also lets
do this other thing" I cringe, it is automatic, sorry :-\

For reviewing its soooo much better to see things nicely separated, and
sometimes I like one part but not the other, so I pick one and continue
discussion on the other, etc.

- Arnaldo

> 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