[dpdk-dev] 回复: [RFC PATCH v3 1/5] eal: add new definitions for wait scheme

[Feifei Wang]

> -----邮件原件-----
> 发件人: Stephen Hemminger <stephen at networkplumber.org>
> 发送时间: Thursday, October 14, 2021 1:00 AM
> 收件人: Ananyev, Konstantin <konstantin.ananyev at intel.com>
> 抄送: Feifei Wang <Feifei.Wang2 at arm.com>; Ruifeng Wang
> <Ruifeng.Wang at arm.com>; dev at dpdk.org; nd <nd at arm.com>
> 主题: Re: [dpdk-dev] [RFC PATCH v3 1/5] eal: add new definitions for wait
> scheme
> 
> On Wed, 13 Oct 2021 15:03:56 +0000
> "Ananyev, Konstantin" <konstantin.ananyev at intel.com> wrote:
> 
> > > addr value' can be before other operations.
> > >
> > > > BTW, if we expect memorder to always be a constant, might be
> > > > better BUILD_BUG_ON()?
> > > If I understand correctly, you means we can replace 'assert' by
> 'build_bug_on':
> > > RTE_BUILD_BUG_ON(memorder != __ATOMIC_ACQUIRE && memorder
> > > !=__ATOMIC_RELAXED);
> >
> > Yes, that was my thought.
> > In that case I think we should be able to catch wrong memorder at
> compilation stage.
> 
> Maybe:
>    RTE_BUILD_BUG_ON(!_constant_p(memorder));
>    RTE_BUILD_BUG_ON(memorder != __ATOMIC_ACQUIRE &&
> memorder !=__ATOMIC_RELAXED);
> 
Thanks for your comments. One question for this, I do not know why we should check if memorder is a constant?
Is it to check whether memorder has been assigned or NULL?