Re: [PATCH v1 7/8] perf c2c: Add option '-d llc' for sorting with LLC load

[Leo Yan]

On Tue, Oct 20, 2020 at 09:26:03AM +0200, Jiri Olsa wrote:
> On Thu, Oct 15, 2020 at 03:50:40PM +0100, Leo Yan wrote:
> > Except the existed three display options 'tot', 'rmt', 'lcl', this patch
> > adds option 'llc' so that can sort on LLC load metrics.  The new
> > introduced option can work as a choice if the memory event doesn't
> > contain HITM tags.
> > 
> > For the display with option 'llc', both the "Shared Data Cache Line
> > Table" and "Shared Cache Line Distribution Pareto" have difference
> > comparing to other three display options.
> > 
> > For the "Shared Data Cache Line Table", instead of sorting HITM metrics,
> > it sorts with the LLC hit metrics "tot_llchit".  In this case, users
> > should be interested in LLC related statistics, so the dimensions of
> > total LLC hit is used to replace HITM related dimensions.
> > 
> > For Pareto, every single cache line shows the metrics "cl_llc_hit"
> > instead of "cl_rmt_hitm", and the single cache line view is sorted by
> > metrics "tot_llchit".
> 
> hi,
> I'm getting compilation error on newer gcc:
> 
>   CC       builtin-c2c.o
> builtin-c2c.c: In function ‘perf_c2c__report’:
> builtin-c2c.c:1979:9: error: ‘sort_str’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
>  1979 |  return hpp_list__parse(&c2c_hists->list, output, sort);
>       |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> builtin-c2c.c:2900:27: note: ‘sort_str’ was declared here
>  2900 |  const char *output_str, *sort_str;
>       |                           ^~~~~~~~

Sorry for this building error.  I didn't detect this error on both
Arm64 and x86;  will fix it.

Thanks,
Leo