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

[Arnaldo Carvalho de Melo]

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@xxxxxxxxxx>
> > > Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> > > ---
> > >  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
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