Re: [PATCH] rcu-scale: change rcu-scale report.

[Han, Jiangong]

and the new edition for reviewing is here: 
https://lkml.org/lkml/2021/6/22/327

Thanks for you time.
Br,
Jiangong.


在 2021/6/22 下午6:48, Han, Jiangong 写道:
> Sorry, my the comment is wrong, and the correct comment should be like 
> below, and I had modify this, and I had resend one more applying 
> review patch email for this.
>
> Thanks for you time.
>
> Br,
>
> Jiangong.
>
> ----------------------------------
>     rcu-scale: rcu-scale returns one less than the real number of gps 
> in the dmesg report.
>
>     The dmesg report on rcu-scale shows there are N grace periods, and 
> gps
>     are listed from 0 to N.
>     This commit make writer_n_durations stores the counts of gps,
>     and shows there are N+1 gps, change the listed gps index begin 
> from 0 to N.
>
>     From
>         [ 8306.087880] rcu-scale: writer 0 gps: 133
>         ......
>         [ 8307.864630] rcu-scale:    0 writer-duration:     0 44003961
>         [ 8307.935711] rcu-scale:    0 writer-duration:     1 32003582
>         ......
>         [ 8316.472860] rcu-scale:    0 writer-duration:   132 28004391
>         [ 8316.538498] rcu-scale:    0 writer-duration:   133 27996410
>
>     to
>         [ 8306.087880] rcu-scale: writer 0 gps: 134
>         ......
>         [ 8307.864630] rcu-scale:    0 writer-duration:     0 44003961
>         [ 8307.935711] rcu-scale:    0 writer-duration:     1 32003582
>         ......
>         [ 8316.472860] rcu-scale:    0 writer-duration:   132 28004391
>         [ 8316.538498] rcu-scale:    0 writer-duration:   133 27996410
>
> ----------------------------------
>
>
>
>  2021/6/10 上午4:37, Paul E. McKenney 写道:
> > [Please note: This e-mail is from an EXTERNAL e-mail address]
> >
> > On Sat, Jun 05, 2021 at 03:00:19PM +0800, Jiangong.Han wrote:
> > > The report on rcu-scale shows there are N grace periods, and gps
> > > are listed from 0 to N-1.
> > > This commit make writer_n_durations stores the counts of gps,
> > > change the listed gps index begin from 1 to N.
> > >
> > > From
> > >      [ 8306.087880] rcu-scale: writer 0 gps: 133
> > >      ......
> > >      [ 8307.864630] rcu-scale:    0 writer-duration:     0 44003961
> > >      [ 8307.935711] rcu-scale:    0 writer-duration:     1 32003582
> > >      ......
> > >      [ 8316.472860] rcu-scale:    0 writer-duration:   131 28004391
> > >      [ 8316.538498] rcu-scale:    0 writer-duration:   132 27996410
> > >
> > > to
> > >      [ 8306.087880] rcu-scale: writer 0 gps: 133
> > >      ......
> > >      [ 8307.864630] rcu-scale:    0 writer-duration:     1 44003961
> > >      [ 8307.935711] rcu-scale:    0 writer-duration:     2 32003582
> > >      ......
> > >      [ 8316.472860] rcu-scale:    0 writer-duration:   132 28004391
> > >      [ 8316.538498] rcu-scale:    0 writer-duration:   133 27996410
> > >
> > > Signed-off-by: Jiangong.Han <jiangong.han@xxxxxxxxxxxxx>
> > You lost me on this one.  Why is this helpful?  And how does the change
> > shown below actually result in the output shown above, given that
> > rcu_scale_cleanup() still starts j at zero?
> >
> >                                                          Thanx, Paul
> >
> > > ---
> > >   kernel/rcu/rcuscale.c | 4 ++--
> > >   1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c
> > > index dca51fe9c73f..2cc34a22a506 100644
> > > --- a/kernel/rcu/rcuscale.c
> > > +++ b/kernel/rcu/rcuscale.c
> > > @@ -487,7 +487,7 @@ rcu_scale_writer(void *arg)
> > >        if (gp_async) {
> > >                cur_ops->gp_barrier();
> > >        }
> > > -     writer_n_durations[me] = i_max;
> > > +     writer_n_durations[me] = i_max + 1;
> > >        torture_kthread_stopping("rcu_scale_writer");
> > >        return 0;
> > >   }
> > > @@ -561,7 +561,7 @@ rcu_scale_cleanup(void)
> > >                        wdpp = writer_durations[i];
> > >                        if (!wdpp)
> > >                                continue;
> > > -                     for (j = 0; j <= writer_n_durations[i]; j++) {
> > > +                     for (j = 0; j < writer_n_durations[i]; j++) {
> > >                                wdp = &wdpp[j];
> > >                                pr_alert("%s%s %4d writer-duration: 
> > > %5d %llu\n",
> > >                                        scale_type, SCALE_FLAG,
> > > --
> > > 2.17.1