linux-kernel - Re: [PATCH 2/5] perf report: Show message for percent limit on stdio

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Date:	Thu, 31 Mar 2016 01:12:36 +0900
From:	Namhyung Kim <namhyung@...nel.org>
To:	Arnaldo Carvalho de Melo <acme@...nel.org>
Cc:	Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Jiri Olsa <jolsa@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	David Ahern <dsahern@...il.com>,
	Andi Kleen <andi@...stfloor.org>,
	Stephane Eranian <eranian@...gle.com>,
	Wang Nan <wangnan0@...wei.com>
Subject: Re: [PATCH 2/5] perf report: Show message for percent limit on stdio

Hi Arnaldo,

On Wed, Mar 30, 2016 at 11:12:42AM -0300, Arnaldo Carvalho de Melo wrote:
> Em Fri, Feb 26, 2016 at 09:13:17PM +0900, Namhyung Kim escreveu:
> > When the hierarchy mode is used, some entries might be omiited due to a
> > percent limit or filter.  In this case the output hierarchy is different
> > than other entries.  Add an informative message to users about this.
> > 
> > For example, when 4% of percent limit is applied:
> 
> Hi Namhyung, while replying to a message about parent sorting being
> broken I noticed that the code to show a message about --percent-limit
> seems to be only present on --hierachy mode, could you please consider
> adding it to the non-hierarchy case?

Currently the 'no entry' message is for hist entries, not for call
chains.  With --percent-limit option the callchains below the limit
are always silently discarded.  This is same for the hierarchy mode
too.

Thanks,
Namhyung


> 
> Thanks,
> 
> - Arnaldo
>  
> > 
> > After:
> > 
> >   #       Overhead  Command / Shared Object / Symbol
> >   # ..............  ..........................................
> >   #
> >       49.09%        swapper
> >          48.67%        [kernel.vmlinux]
> >             34.42%        [k] intel_idle
> >       11.51%        firefox
> >           8.87%        libpthread-2.22.so
> >              6.60%        [.] __GI___libc_recvmsg
> >       10.49%        gnome-shell
> >           4.74%        libc-2.22.so
> >                           no entry >= 4.00%
> >       10.08%        Xorg
> >           6.11%        libc-2.22.so
> >              5.27%        [.] __memcpy_sse2_unaligned
> >        6.15%        perf
> >                        no entry >= 4.00%
> > 
> > Suggested-by: Arnaldo Carvalho de Melo <acme@...nel.org>
> > Signed-off-by: Namhyung Kim <namhyung@...nel.org>
> > ---
> >  tools/perf/ui/stdio/hist.c | 17 +++++++++++++++++
> >  1 file changed, 17 insertions(+)
> > 
> > diff --git a/tools/perf/ui/stdio/hist.c b/tools/perf/ui/stdio/hist.c
> > index 435eaaaf2f1d..b3bdfcb245f9 100644
> > --- a/tools/perf/ui/stdio/hist.c
> > +++ b/tools/perf/ui/stdio/hist.c
> > @@ -628,6 +628,7 @@ size_t hists__fprintf(struct hists *hists, bool show_header, int max_rows,
> >  	bool first = true;
> >  	size_t linesz;
> >  	char *line = NULL;
> > +	unsigned indent;
> >  
> >  	init_rem_hits();
> >  
> > @@ -704,6 +705,8 @@ print_entries:
> >  		goto out;
> >  	}
> >  
> > +	indent = hists__overhead_width(hists) + 4;
> > +
> >  	for (nd = rb_first(&hists->entries); nd; nd = __rb_hierarchy_next(nd, HMD_FORCE_CHILD)) {
> >  		struct hist_entry *h = rb_entry(nd, struct hist_entry, rb_node);
> >  		float percent;
> > @@ -720,6 +723,20 @@ print_entries:
> >  		if (max_rows && ++nr_rows >= max_rows)
> >  			break;
> >  
> > +		/*
> > +		 * If all children are filtered out or percent-limited,
> > +		 * display "no entry >= x.xx%" message.
> > +		 */
> > +		if (!h->leaf && !hist_entry__has_hierarchy_children(h, min_pcnt)) {
> > +			int nr_sort = hists->hpp_list->nr_sort_keys;
> > +
> > +			print_hierarchy_indent(sep, nr_sort + h->depth + 1, spaces, fp);
> > +			fprintf(fp, "%*sno entry >= %.2f%%\n", indent, "", min_pcnt);
> > +
> > +			if (max_rows && ++nr_rows >= max_rows)
> > +				break;
> > +		}
> > +
> >  		if (h->ms.map == NULL && verbose > 1) {
> >  			__map_groups__fprintf_maps(h->thread->mg,
> >  						   MAP__FUNCTION, fp);
> > -- 
> > 2.7.1