Re: [PATCH] Export shmem_file_setup and shmem_getpage for DRM-GEM

[Stephane Marchesin]

On 8/6/08, Arjan van de Ven <arjan@xxxxxxxxxxxxx> wrote:
> On Wed, 6 Aug 2008 18:20:40 +0200
>  "Stephane Marchesin" <marchesin@xxxxxxxxxxxxxxxxx> wrote:
>
>  > On 8/5/08, Keith Packard <keithp@xxxxxxxxxx> wrote:
>  > > On Mon, 2008-08-04 at 22:25 -0400, John Stoffel wrote:
>  > >
>  > >  > What about the onboard memory of graphics cards?  Isn't that
>  > >  > where Textures and such are stored as well?  So once something
>  > >  > is loaded to the card, shouldn't you be able to free it in
>  > >  > system memory?  Or swap it out ahead of time?
>  > >
>  > >
>  > > Right now, I'm working only on Intel integrated graphics, which
>  > > doesn't have any on-board memory. My thinking is that we'd best
>  > > solve the easiest case first before attempting the harder discrete
>  > > graphics driver. Plus, Intel pays me do do integrated graphics, so
>  > > I have an incentive.
>  > >
>  >
>  > Right, but it sounds adventurous to merge this work upstream before it
>  > is generic enough to work on discrete cards. Right now it only works
>  > on intel integrated cards ; integrated cards are one business,
>  > discrete are a completely different world and the issues afoot
>  > completely different.
>  >
>  > Should this go upstream, the kernel guys have to keep in mind and
>  > accept the possibility that another memory manager might be needed at
>  > some point.
>
>
> the ATI driver guys already have the interface working.
>

No they don't. There is only preliminary code.

>  In addition.. since when is "oh you must also make it work for THAT" a
>  requirement? Traditionally, it's up to the second person to make
>  generic code work for them (within reason of course, but I'll argue
>  that the bar of reasonableness has been met here)
>

Right, but the current code will basically force the discrete card
drivers to implement backing store for all allocations. Do we want
this ? Also, for cards that can handle page-based memory allocations,
there is no way to make use of this feature, do we want this too ?

Stephane
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