Re: [PATCH] perf c2c: Fix sorting.

[Arnaldo Carvalho de Melo <acme@redhat.com>]

Em Thu, Jan 09, 2020 at 10:58:43AM +0100, Michael Petlan escreveu:
> On Wed, 8 Jan 2020, Andres Freund wrote:
> > Commit 722ddfde366f ("perf tools: Fix time sorting") changed -
> > correctly so - hist_entry__sort to return int64. Unfortunately several
> > of the builtin-c2c.c comparison routines only happened to work due the
> > cast caused by the wrong return type.
> > 
> > This causes meaningless ordering of both the cacheline list, and the
> > cacheline details page. E.g a simple
> >   perf c2c record -a sleep 3
> >   perf c2c report
> > will result in cacheline table like
> >   =================================================
> >              Shared Data Cache Line Table
> >   =================================================
> >   #
> >   #        ----------- Cacheline ----------    Total      Tot  ----- LLC Load Hitm -----  ---- Store Reference ----  --- Load Dram ----      LLC    Total  ----- Core Load Hit -----  -- LLC Load Hit --
> >   # Index             Address  Node  PA cnt  records     Hitm    Total      Lcl      Rmt    Total    L1Hit   L1Miss       Lcl       Rmt  Ld Miss    Loads       FB       L1       L2       Llc       Rmt
> >   # .....  ..................  ....  ......  .......  .......  .......  .......  .......  .......  .......  .......  ........  ........  .......  .......  .......  .......  .......  ........  ........
> >   #
> >         0      0x7f0d27ffba00   N/A       0       52    0.12%       13        6        7       12       12        0         0         7       14       40        4       16        0         0         0
> >         1      0x7f0d27ff61c0   N/A       0     6353   14.04%     1475      801      674      779      779        0         0       718     1392     5574     1299     1967        0       115         0
> >         2      0x7f0d26d3ec80   N/A       0       71    0.15%       16        4       12       13       13        0         0        12       24       58        1       20        0         9         0
> >         3      0x7f0d26d3ec00   N/A       0       98    0.22%       23       17        6       19       19        0         0         6       12       79        0       40        0        10         0
> > i.e. with the list not being ordered by Total Hitm.
> > 
> > Fixes: 722ddfde366f ("perf tools: Fix time sorting")
> > Signed-off-by: Andres Freund <andres@anarazel.de>
> 
> Tested on top of Arnaldo's perf/core branch. After the patch, the rows
> are ordered by Tot Hitm.
> 
> Tested-by: Michael Petlan <mpetlan@redhat.com>

Jiri, so you think we should use a different Fixes: cset? Or plain
remove it? I haven't checked it, just trying to figure out if you guys
came up with a conclusion so that I can review/apply.

- Arnaldo
 
> > Cc: Jiri Olsa <jolsa@kernel.org>
> > Cc: Andi Kleen <ak@linux.intel.com>
> > Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> > Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
> > Cc: Michael Petlan <mpetlan@redhat.com>
> > Cc: Namhyung Kim <namhyung@kernel.org>
> > Cc: Peter Zijlstra <peterz@infradead.org>
> > Cc: stable@vger.kernel.org # v3.16+
> > ---
> >  tools/perf/builtin-c2c.c | 10 ++++++----
> >  1 file changed, 6 insertions(+), 4 deletions(-)
> > 
> > diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c
> > index e69f44941aad..f2e9d2b1b913 100644
> > --- a/tools/perf/builtin-c2c.c
> > +++ b/tools/perf/builtin-c2c.c
> > @@ -595,8 +595,8 @@ tot_hitm_cmp(struct perf_hpp_fmt *fmt __maybe_unused,
> >  {
> >  	struct c2c_hist_entry *c2c_left;
> >  	struct c2c_hist_entry *c2c_right;
> > -	unsigned int tot_hitm_left;
> > -	unsigned int tot_hitm_right;
> > +	uint64_t tot_hitm_left;
> > +	uint64_t tot_hitm_right;
> >  
> >  	c2c_left  = container_of(left, struct c2c_hist_entry, he);
> >  	c2c_right = container_of(right, struct c2c_hist_entry, he);
> > @@ -629,7 +629,8 @@ __f ## _cmp(struct perf_hpp_fmt *fmt __maybe_unused,			\
> >  									\
> >  	c2c_left  = container_of(left, struct c2c_hist_entry, he);	\
> >  	c2c_right = container_of(right, struct c2c_hist_entry, he);	\
> > -	return c2c_left->stats.__f - c2c_right->stats.__f;		\
> > +	return (uint64_t) c2c_left->stats.__f -				\
> > +	       (uint64_t) c2c_right->stats.__f;				\
> >  }
> >  
> >  #define STAT_FN(__f)		\
> > @@ -682,7 +683,8 @@ ld_llcmiss_cmp(struct perf_hpp_fmt *fmt __maybe_unused,
> >  	c2c_left  = container_of(left, struct c2c_hist_entry, he);
> >  	c2c_right = container_of(right, struct c2c_hist_entry, he);
> >  
> > -	return llc_miss(&c2c_left->stats) - llc_miss(&c2c_right->stats);
> > +	return (uint64_t) llc_miss(&c2c_left->stats) -
> > +	       (uint64_t) llc_miss(&c2c_right->stats);
> >  }
> >  
> >  static uint64_t total_records(struct c2c_stats *stats)
> > -- 
> > 2.25.0.rc1
> > 
> >