linux-kernel - Re: [PATCH v2 4/7] perf diff: Use hists to manage basic blocks per symbol

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Date:   Wed, 12 Jun 2019 09:44:17 +0200
From:   Jiri Olsa <jolsa@...hat.com>
To:     "Jin, Yao" <yao.jin@...ux.intel.com>
Cc:     acme@...nel.org, jolsa@...nel.org, peterz@...radead.org,
        mingo@...hat.com, alexander.shishkin@...ux.intel.com,
        Linux-kernel@...r.kernel.org, ak@...ux.intel.com,
        kan.liang@...el.com, yao.jin@...el.com
Subject: Re: [PATCH v2 4/7] perf diff: Use hists to manage basic blocks per
 symbol

On Wed, Jun 12, 2019 at 02:11:44PM +0800, Jin, Yao wrote:
> 
> 
> On 6/11/2019 4:56 PM, Jiri Olsa wrote:
> > On Sat, Jun 08, 2019 at 07:41:47PM +0800, Jin, Yao wrote:
> > > 
> > > 
> > > On 6/5/2019 7:44 PM, Jiri Olsa wrote:
> > > > On Mon, Jun 03, 2019 at 10:36:14PM +0800, Jin Yao wrote:
> > > > 
> > > > SNIP
> > > > 
> > > > > diff --git a/tools/perf/util/sort.h b/tools/perf/util/sort.h
> > > > > index 43623fa..d1641da 100644
> > > > > --- a/tools/perf/util/sort.h
> > > > > +++ b/tools/perf/util/sort.h
> > > > > @@ -79,6 +79,9 @@ struct hist_entry_diff {
> > > > >    		/* HISTC_WEIGHTED_DIFF */
> > > > >    		s64	wdiff;
> > > > > +
> > > > > +		/* PERF_HPP_DIFF__CYCLES */
> > > > > +		s64	cycles;
> > > > >    	};
> > > > >    };
> > > > > @@ -143,6 +146,9 @@ struct hist_entry {
> > > > >    	struct branch_info	*branch_info;
> > > > >    	long			time;
> > > > >    	struct hists		*hists;
> > > > > +	void			*block_hists;
> > > > > +	int			block_idx;
> > > > > +	int			block_num;
> > > > >    	struct mem_info		*mem_info;
> > > > >    	struct block_info	*block_info;
> > > > 
> > > > could you please not add the new block* stuff in here,
> > > > and instead use the "c2c model" and use yourr own struct
> > > > on top of hist_entry? we are trying to librarize this
> > > > stuff and keep only necessary things in here..
> > > > 
> > > > you're already using hist_entry_ops, so should be easy
> > > > 
> > > > something like:
> > > > 
> > > > 	struct block_hist_entry {
> > > > 		void			*block_hists;
> > > > 		int			block_idx;
> > > > 		int			block_num;
> > > > 		struct block_info	*block_info;
> > > > 
> > > > 		struct hist_entry	he;
> > > > 	};
> > > > 
> > > > 
> > > > 
> > > > jirka
> > > > 
> > > 
> > > Hi Jiri,
> > > 
> > > After more considerations, maybe I can't move these stuffs from hist_entry
> > > to block_hist_entry.
> > 
> > why?
> > 
> > > 
> > > Actually we use 2 kinds of hist_entry in this patch series. On kind of
> > > hist_entry is for symbol/function. The other kind of hist_entry is for basic
> > > block.
> > 
> > correct
> > 
> > so the way I see it the processing goes like this:
> > 
> > 
> > 1) there's standard hist_entry processing ending up
> >     with evsel->hists->rb_root full of hist entries
> > 
> > 2) then you process every hist_entry and create
> >     new 'struct hists' for each and fill it with
> >     symbol counts data
> > 
> > 
> > 
> > you could add 'struct hist_entry_ops' for the 1) processing
> > that adds the 'struct hists' object for each hist_entry
> > 
> > and add another 'struct hist_entry_ops' for 2) processing
> > to carry the block data for each hist_entry
> > 
> > jirka
> > 
> 
> Hi Jiri,
> 
> Yes, I can use two hist_entry_ops but one thing is still difficult to handle
> that is the printing of blocks.
> 
> One function may contain multiple blocks so I add 'block_num' in 'struct
> hist_entry' to record the number of blocks.
> 
> In patch "perf diff: Print the basic block cycles diff", I reuse most of
> current code to print the blocks. The major change is:
> 
>  static int hist_entry__fprintf(struct hist_entry *he, size_t size,
>                                char *bf, size_t bfsz, FILE *fp,
>                                bool ignore_callchains) {
> 
> +       if (he->block_hists)
> +               return hist_entry__block_fprintf(he, bf, size, fp);
> +


you could do it the way we do hierarchy and have
something like 'symbol_conf.report_block'

        if (symbol_conf.report_hierarchy)
                return hist_entry__hierarchy_fprintf(he, &hpp, hists, fp);

and in hist_entry__block_fprintf you cast the hist_entry
to your struct.. so you'll have all the data

jirka

>         hist_entry__snprintf(he, &hpp);
> }
> 
> +static int hist_entry__block_fprintf(struct hist_entry *he,
> +                                    char *bf, size_t size,
> +                                    FILE *fp)
> +{
> +       int ret = 0;
> +
> +       for (int i = 0; i < he->block_num; i++) {
> +               struct perf_hpp hpp = {
> +                       .buf            = bf,
> +                       .size           = size,
> +                       .skip           = false,
> +               };
> +
> +               he->block_idx = i;
> +               hist_entry__snprintf(he, &hpp);
> +
> +               if (!hpp.skip)
> +                       ret += fprintf(fp, "%s\n", bf);
> +       }
> +
> +       return ret;
> +}
> +
> 
> So it looks at least I need to add 'block_num' to 'struct hist_entry',
> otherwise I can't reuse most of codes.
> 
> Any idea for 'block_num'?
> 
> Thanks
> Jin Yao