[dpdk-dev] 回复: 回复: [PATCH] app/eventdev: remove unnecessary barrier for order test

[Feifei Wang <Feifei.Wang2@arm.com>]

> -----邮件原件-----
> 发件人: Jerin Jacob <jerinjacobk@gmail.com>
> 发送时间: 2021年5月18日 22:05
> 收件人: Feifei Wang <Feifei.Wang2@arm.com>
> 抄送: jerinj@marvell.com; Ruifeng Wang <Ruifeng.Wang@arm.com>;
> Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>; dev@dpdk.org;
> nd <nd@arm.com>
> 主题: Re: [dpdk-dev] 回复: [PATCH] app/eventdev: remove unnecessary
> barrier for order test
> 
> On Tue, May 18, 2021 at 2:57 PM Feifei Wang <Feifei.Wang2@arm.com>
> wrote:
> >
> > Hi, Jerin
> >
> > Sorry to disturb you. Would you please help me review this patch, thanks
> very much.
> 
> In slowpath, I thought of having this barrier. But I agree that it can be
> removed.
> Since this is not bug. We will merge this patch in next release.

That's Ok. Thanks very much for your reviewing.

Best Regards
Feifei
> 
> 
> 
> >
> >
> > Best Regards
> > Feifei
> >
> > > -----Original Message-----
> > > From: Feifei Wang <feifei.wang2@arm.com>
> > > Sent: Monday, May 10, 2021 2:12 PM
> > > To: jerinj@marvell.com
> > > Cc: dev@dpdk.org; nd <nd@arm.com>; Feifei Wang
> > > <Feifei.Wang2@arm.com>; Ruifeng Wang <Ruifeng.Wang@arm.com>;
> > > Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
> > > Subject: [PATCH] app/eventdev: remove unnecessary barrier for order
> > > test
> > >
> > > For "order_launch_lcores" function, wmb after that the main lcore
> > > updates the variable "t->err", which represents the end of the test
> > > signal, is unnecessary. Because after the main lcore updates this
> > > siginal variable, it will jump out of the launch function loop, and
> > > wait other lcores stop or return error in the main function(evt_main.c).
> > > During this time, there is no storing operation and thus no need for wmb.
> > >
> > > Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
> > > Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> > > Reviewed-by: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
> > > ---
> > >  app/test-eventdev/test_order_common.c | 1 -
> > >  1 file changed, 1 deletion(-)
> > >
> > > diff --git a/app/test-eventdev/test_order_common.c b/app/test-
> > > eventdev/test_order_common.c index 04456d56db..d7760061ba 100644
> > > --- a/app/test-eventdev/test_order_common.c
> > > +++ b/app/test-eventdev/test_order_common.c
> > > @@ -308,7 +308,6 @@ order_launch_lcores(struct evt_test *test,
> > > struct evt_options *opt,
> > >                               rte_event_dev_dump(opt->dev_id, stdout);
> > >                               evt_err("No schedules for seconds,
> > > deadlock");
> > >                               t->err = true;
> > > -                             rte_smp_wmb();
> > >                               break;
> > >                       }
> > >                       old_remaining = remaining;
> > > --
> > > 2.25.1
> > >
> >