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Date: Mon, 19 Nov 2018 04:29:29 -0800
From: Matthew Wilcox <willy@infradead.org>
Subject: Re: [Xen-devel] [PATCH 5/9] drm/xen/xen_drm_front_gem.c: Convert to
 use vm_insert_range
Message-ID: <20181119122929.GA394@bombadil.infradead.org>
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To: Oleksandr Andrushchenko <andr2000@gmail.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>, Andrew Morton <akpm@linux-foundation.org>, Michal Hocko <mhocko@suse.com>, oleksandr_andrushchenko@epam.com, airlied@linux.ie, Linux-MM <linux-mm@kvack.org>, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, xen-devel@lists.xen.org

On Mon, Nov 19, 2018 at 01:02:46PM +0200, Oleksandr Andrushchenko wrote:
> On 11/19/18 12:42 PM, Souptick Joarder wrote:
> > On Mon, Nov 19, 2018 at 3:22 PM Oleksandr Andrushchenko
> > <andr2000@gmail.com> wrote:
> > > > -     unsigned long addr = vma->vm_start;
> > > > -     int i;
> > > > +     int err;
> > > I would love to keep ret, not err
> > Sure, will add it in v2.
> > But I think, err is more appropriate here.
> 
> I used "ret" throughout the driver, so this is just to remain consistent:
> 
> grep -rnw err drivers/gpu/drm/xen/ | wc -l
> 0
> grep -rnw ret drivers/gpu/drm/xen/ | wc -l
> 204

It's your driver, so that's fine.  The reason we chose 'err' over 'ret'
is that there's a history of errno vs VM_FAULT_xxx code confusion in
this area.  Naming a variable 'err' makes it clear this is an errno and
not a vm_fault_t.

> > > With the above fixed,
> > > 
> > > Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>

Thanks.