Date: Thu, 13 Aug 2015 17:11:21 -0400
From: Jerome Glisse <jglisse@redhat.com>
To: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org,
        Christophe Harle <charle@nvidia.com>, Duncan Poole <dpoole@nvidia.com>,
        Sherry Cheung <SCheung@nvidia.com>, Subhash Gutti <sgutti@nvidia.com>,
        John Hubbard <jhubbard@nvidia.com>,
        Mark Hairgrove <mhairgrove@nvidia.com>,
        Lucien Dunning <ldunning@nvidia.com>,
        Cameron Buschardt <cabuschardt@nvidia.com>,
        Arvind Gopalakrishnan <arvindg@nvidia.com>,
        Haggai Eran <haggaie@mellanox.com>,
        Shachar Raindel <raindel@mellanox.com>,
        Liran Liss <liranl@mellanox.com>
Subject: Re: [RFC PATCH 4/8 v2] IB/odp/hmm: prepare for HMM code path.
Message-ID: <20150813211121.GA10678@redhat.com>
References: <1439493653-1191-1-git-send-email-jglisse@redhat.com>
 <1439493653-1191-5-git-send-email-jglisse@redhat.com>
 <20150813201335.GA22581@obsidianresearch.com>
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On Thu, Aug 13, 2015 at 02:13:35PM -0600, Jason Gunthorpe wrote:
> On Thu, Aug 13, 2015 at 03:20:49PM -0400, J?r?me Glisse wrote:
>   
> > +#if IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM)
> > +#else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM */
> 
> Yuk, what is wrong with
> 
>  #if !IS_ENABLED(...)
> 
> ?

Just that latter patches add code btw #if and #else, and that
originaly it was a bigger patch that added the #if code #else
at the same time. Hence why this patch looks like this.

> 
> > -#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
> > +#if IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING)
> > +#if IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM)
> > +#else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM */
> 
> Double yuk
> 
>  #if !(IS_ENABLED(..) && IS_ENABLED(..))
> 
> ?

Same reason as above.


> And the #ifdefs suck, as many as possible should be normal if
> statements, and one should think carefully if we really need to remove
> fields from structures..

My patch only add #if, i am not responsible for previous code
that used #ifdef, i was told to convert to #if and that's what
i am doing.

Regarding fields, yes this is intentional, ODP is an infrastructure
that is private to infiniband and thus needs more fields inside ib
struct. While HMM is intended to be a common infrastructure not only
for ib device but for other kind of devices too.

Cheers,
J?r?me
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