Re: [PATCH v2] perf stat: Append to default list if use -e +event

Jiri Olsa
2021-01-21T02:40:02Z

On Mon, Jan 18, 2021 at 12:54:37PM +0800, Jin, Yao wrote:
> Hi Jiri,
>
> On 1/12/2021 6:08 PM, Jiri Olsa wrote:
> > On Mon, Jan 04, 2021 at 10:18:37AM +0800, Jin Yao wrote:
> > > The default event list includes the most common events which are widely
> > > used by users. But with -e option, the current perf only counts the events
> > > assigned by -e option. Users may want to collect some extra events with
> > > the default list. For this case, users have to manually add all the events
> > > from the default list. It's inconvenient. Also, users may don't know how to
> > > get the default list.
> > >
> > > Now it supports a simple syntax: -e +event
> > >
> > > The prefix '+' tells perf to append this event (or event list) to default
> > > event list.
> > >
> > > Before:
> > >
> > > root@kbl-ppc:~# ./perf stat -e power/energy-pkg/ -a -- sleep 1
> > >
> > > Performance counter stats for 'system wide':
> > >
> > > 2.04 Joules power/energy-pkg/
> > >
> > > 1.000863884 seconds time elapsed
> > >
> > > After:
> > >
> > > root@kbl-ppc:~# ./perf stat -e +power/energy-pkg/ -a -- sleep 1
> > >
> > > Performance counter stats for 'system wide':
> > >
> > > 2.11 Joules +power/energy-pkg/ # 0.000 K/sec
> >
> > I dont think we should print the extra '+' prefix
> >
> > jirka
> >
> > > 8,007.17 msec cpu-clock # 7.993 CPUs utilized
> > > 125 context-switches # 0.016 K/sec
> > > 8 cpu-migrations # 0.001 K/sec
> > > 2 page-faults # 0.000 K/sec
> > > 8,520,084 cycles # 0.001 GHz
> > > 2,808,302 instructions # 0.33 insn per cycle
> > > 555,427 branches # 0.069 M/sec
> > > 59,005 branch-misses # 10.62% of all branches
> > >
> > > 1.001832003 seconds time elapsed
> > >
> > > Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
> >
>
> Printing '+' prefix is the original behavior.
>
> Without this patch,
>
> root@kbl-ppc:# ./perf stat -e +power/energy-pkg/ -a -- sleep 1
>
> Performance counter stats for 'system wide':
>
> 2.02 Joules +power/energy-pkg/
>
> 1.000859434 seconds time elapsed
>
> The '+' prefix is printed. So I finally decide not to remove the '+' prefix
> in order to keep original behavior.

hm, originaly there's no purpose for the '+', right?
it seems it's more like bug then anything else

you added function to the '+' to add default events to specified event,
which I think is good idea, but I don't think we should display the
extra '+' in output

thanks,
jirka