Re: [PATCH/RFC 11/16] perf top: Implement basic parallel processing

[Namhyung Kim <namhyung@kernel.org>]

On Mon, Dec 14, 2015 at 10:35:19AM +0100, Jiri Olsa wrote:
> On Mon, Dec 14, 2015 at 10:23:43AM +0100, Jiri Olsa wrote:
> > On Thu, Dec 10, 2015 at 04:53:30PM +0900, Namhyung Kim wrote:
> > 
> > SNIP
> > 
> > >  
> > > -	perf_top__mmap_read(top);
> > > -
> > >  	ret = -1;
> > > -	if (pthread_create(&thread, NULL, (use_browser > 0 ? display_thread_tui :
> > > -							    display_thread), top)) {
> > > -		ui__error("Could not create display thread.\n");
> > > +	readers = calloc(sizeof(pthread_t), top->evlist->nr_mmaps);
> > > +	if (readers == NULL)
> > >  		goto out_delete;
> > > -	}
> > >  
> > > -	if (top->realtime_prio) {
> > > -		struct sched_param param;
> > > +	rargs = calloc(sizeof(*rargs), top->evlist->nr_mmaps);
> > > +	if (rargs == NULL)
> > > +		goto out_free;
> > >  
> > > -		param.sched_priority = top->realtime_prio;
> > > -		if (sched_setscheduler(0, SCHED_FIFO, &param)) {
> > > -			ui__error("Could not set realtime priority.\n");
> > > -			goto out_join;
> > > -		}
> > > +	hists = calloc(sizeof(*hists), top->evlist->nr_mmaps * top->evlist->nr_entries);
> > > +	if (hists == NULL)
> > > +		goto out_free;
> > > +
> > > +	for (i = 0; i < top->evlist->nr_mmaps * top->evlist->nr_entries; i++)
> > > +		__hists__init(&hists[i]);
> > > +
> > > +	for (i = 0; i < top->evlist->nr_mmaps; i++) {
> > > +		struct reader_arg *rarg = &rargs[i];
> > > +
> > > +		rarg->idx = i;
> > > +		rarg->top = top;
> > > +		rarg->hists = &hists[i * top->evlist->nr_entries];
> > > +
> > > +		perf_top__mmap_read(rarg);
> > >  	}
> > > +	collect_hists(top, hists);
> > 
> > hum, what's the reason for calling perf_top__mmap_read
> > and collect_hists in here?
> 
> nah it's for initial data so ui thread has something to display right? ;-)

Right, the logic was already there.  Without it, the initial update
(after 2 seconds) looks too long for users.


> 
> > 
> > also calling collect_hists on hists array pointer seems wrong
> 
> still 'collect_hists(&hists[0]);' would seem more review friendly

Will change!

Thanks,
Namhyung