Re: [PATCH v2 2/2] perf top: support hotkey to change sort order

[Arnaldo Carvalho de Melo]

Em Mon, Mar 30, 2020 at 08:43:47AM +0800, Jin, Yao escreveu:
> Hi Arnaldo,
> 
> The v2 patch zeros the history when pressing the hotkey. Is it OK?

Yeah, I've applied it to my perf/core branch.

Thanks,

- Arnaldo
 
> Thanks
> Jin Yao
> 
> On 3/25/2020 6:07 AM, Jin Yao wrote:
> > It would be nice if we can use a hotkey in perf top browser to
> > select a event for sorting.
> > 
> > For example,
> > perf top --group -e cycles,instructions,cache-misses
> > 
> > Samples
> >                  Overhead  Shared Object             Symbol
> >    40.03%  45.71%   0.03%  div                       [.] main
> >    20.46%  14.67%   0.21%  libc-2.27.so              [.] __random_r
> >    20.01%  19.54%   0.02%  libc-2.27.so              [.] __random
> >     9.68%  10.68%   0.00%  div                       [.] compute_flag
> >     4.32%   4.70%   0.00%  libc-2.27.so              [.] rand
> >     3.84%   3.43%   0.00%  div                       [.] rand@plt
> >     0.05%   0.05%   2.33%  libc-2.27.so              [.] __strcmp_sse2_unaligned
> >     0.04%   0.08%   2.43%  perf                      [.] perf_hpp__is_dynamic_en
> >     0.04%   0.02%   6.64%  perf                      [.] rb_next
> >     0.04%   0.01%   3.87%  perf                      [.] dso__find_symbol
> >     0.04%   0.04%   1.77%  perf                      [.] sort__dso_cmp
> > 
> > When user press hotkey '2' (event index, starting from 0), it indicates
> > to sort output by the third event in group (cache-misses).
> > 
> > Samples
> >                  Overhead  Shared Object               Symbol
> >     4.07%   1.28%   6.68%  perf                        [.] rb_next
> >     3.57%   3.98%   4.11%  perf                        [.] __hists__insert_output
> >     3.67%  11.24%   3.60%  perf                        [.] perf_hpp__is_dynamic_e
> >     3.67%   3.20%   3.20%  perf                        [.] hpp__sort_overhead
> >     0.81%   0.06%   3.01%  perf                        [.] dso__find_symbol
> >     1.62%   5.47%   2.51%  perf                        [.] hists__match
> >     2.70%   1.86%   2.47%  libc-2.27.so                [.] _int_malloc
> >     0.19%   0.00%   2.29%  [kernel]                    [k] copy_page
> >     0.41%   0.32%   1.98%  perf                        [.] hists__decay_entries
> >     1.84%   3.67%   1.68%  perf                        [.] sort__dso_cmp
> >     0.16%   0.00%   1.63%  [kernel]                    [k] clear_page_erms
> > 
> > Now the output is sorted by cache-misses.
> > 
> >   v2:
> >   ---
> >   Zero the history if hotkey is pressed.
> > 
> > Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
> > ---
> >   tools/perf/builtin-top.c | 11 +++++++++--
> >   1 file changed, 9 insertions(+), 2 deletions(-)
> > 
> > diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
> > index 494c7b9a1022..29ddae7e1805 100644
> > --- a/tools/perf/builtin-top.c
> > +++ b/tools/perf/builtin-top.c
> > @@ -616,6 +616,7 @@ static void *display_thread_tui(void *arg)
> >   		.arg		= top,
> >   		.refresh	= top->delay_secs,
> >   	};
> > +	int ret;
> >   	/* In order to read symbols from other namespaces perf to  needs to call
> >   	 * setns(2).  This isn't permitted if the struct_fs has multiple users.
> > @@ -626,6 +627,7 @@ static void *display_thread_tui(void *arg)
> >   	prctl(PR_SET_NAME, "perf-top-UI", 0, 0, 0);
> > +repeat:
> >   	perf_top__sort_new_samples(top);
> >   	/*
> > @@ -638,13 +640,18 @@ static void *display_thread_tui(void *arg)
> >   		hists->uid_filter_str = top->record_opts.target.uid_str;
> >   	}
> > -	perf_evlist__tui_browse_hists(top->evlist, help, &hbt,
> > +	ret = perf_evlist__tui_browse_hists(top->evlist, help, &hbt,
> >   				      top->min_percent,
> >   				      &top->session->header.env,
> >   				      !top->record_opts.overwrite,
> >   				      &top->annotation_opts);
> > -	stop_top();
> > +	if (ret == K_RELOAD) {
> > +		top->zero = true;
> > +		goto repeat;
> > +	} else
> > +		stop_top();
> > +
> >   	return NULL;
> >   }
> > 

-- 

- Arnaldo