Re: [PATCH 1/9] mm: Introduce new vm_insert_range API

From: Mike Rapoport <rppt@linux.ibm.com>
To: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>, Heiko Stuebner <heiko@sntech.de>,
	Peter Zijlstra <peterz@infradead.org>,
	dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
	Linux-MM <linux-mm@kvack.org>,
	linux1394-devel@lists.sourceforge.net,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	oleksandr_andrushchenko@epam.com, joro@8bytes.org,
	Russell King - ARM Linux <linux@armlinux.org.uk>,
	Matthew Wilcox <willy@infradead.org>,
	airlied@linux.ie, linux-arm-kernel@lists.infradead.org,
	linux-rockchip@lists.infradead.org, treding@nvidia.com,
	linux-media@vger.kernel.org, Kees Cook <keescook@chromium.org>,
	pawel@osciak.com, Rik van Riel <riel@surriel.com>,
	iommu@lists.linux-foundation.org, rppt@linux.vnet.ibm.com,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	mchehab@kernel.org, iamjoonsoo.kim@lge.com, vbabka@suse.cz,
	Juergen Gross <jgross@suse.>
Subject: Re: [PATCH 1/9] mm: Introduce new vm_insert_range API
Date: Mon, 19 Nov 2018 08:26:24 -0800	[thread overview]
Message-ID: <20181119162623.GA13200__6723.99487016282$1542644881$gmane$org@rapoport-lnx> (raw)
In-Reply-To: <CAFqt6zbOWX5LUTWwoGDJsGdf+pTR6N1yTPVxyr1W3-6Fte39ww@mail.gmail.com>

On Mon, Nov 19, 2018 at 08:43:09PM +0530, Souptick Joarder wrote:
> Hi Mike,
> 
> On Sat, Nov 17, 2018 at 8:07 PM Matthew Wilcox <willy@infradead.org> wrote:
> >
> > On Sat, Nov 17, 2018 at 12:26:38PM +0530, Souptick Joarder wrote:
> > > On Fri, Nov 16, 2018 at 11:59 PM Mike Rapoport <rppt@linux.ibm.com> wrote:
> > > > > + * vm_insert_range - insert range of kernel pages into user vma
> > > > > + * @vma: user vma to map to
> > > > > + * @addr: target user address of this page
> > > > > + * @pages: pointer to array of source kernel pages
> > > > > + * @page_count: no. of pages need to insert into user vma
> > > > > + *
> > > > > + * This allows drivers to insert range of kernel pages they've allocated
> > > > > + * into a user vma. This is a generic function which drivers can use
> > > > > + * rather than using their own way of mapping range of kernel pages into
> > > > > + * user vma.
> > > >
> > > > Please add the return value and context descriptions.
> > > >
> > >
> > > Sure I will wait for some time to get additional review comments and
> > > add all of those requested changes in v2.
> >
> > You could send your proposed wording now which might remove the need
> > for a v3 if we end up arguing about the wording.
> 
> Does this description looks good ?
> 
> /**
>  * vm_insert_range - insert range of kernel pages into user vma
>  * @vma: user vma to map to
>  * @addr: target user address of this page
>  * @pages: pointer to array of source kernel pages
>  * @page_count: number of pages need to insert into user vma
>  *
>  * This allows drivers to insert range of kernel pages they've allocated
>  * into a user vma. This is a generic function which drivers can use
>  * rather than using their own way of mapping range of kernel pages into
>  * user vma.
>  *
>  * Context - Process context. Called by mmap handlers.

Context:

>  * Return - int error value

Return:

>  * 0                    - OK
>  * -EINVAL              - Invalid argument
>  * -ENOMEM              - No memory
>  * -EFAULT              - Bad address
>  * -EBUSY               - Device or resource busy

I don't think that elaborate description of error values is needed, just "0
on success and error code otherwise" would be sufficient.

>  */
> 

-- 
Sincerely yours,
Mike.

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel