Re: Getting big areas of memory, in 2.3.x?

Pauline Middelink (middelin@polyware.nl)
Fri, 10 Dec 1999 18:10:34 +0100


On Thu, Dec 09, 1999 at 11:50:04PM +0000, Alan Cox wrote:
> I don't know of any capture cards that don't do scatter gather. Most of them
> do scatter gather with skipping and byte alignment so you can DMA around
> other windows.

*Wave*

The zr36120 is such a broken chip... It has one DMA pointer for
the entire field (really two pointers for one frame) it wants
to transfer. No scatter, no gather.

> This is the main point. There are so so few devices that actually _have_ to
> have lots of linear memory it is questionable that it is worth paying the
> price to allow modules to allocate that way

The problem i'm currently running against is the i have to use
kmalloc() with an 2^x order for the amount of pages to alloc.
Unfortuantly I have defined a framebuffer of a maximum size of
about 3.5MB. 896 pages -> thus kmalloc(...,1024) is needed; We
just threw away 128 pages or 512K :(

Met vriendelijke groet,
Pauline Middelink

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