Re: [RFC] mmap(MAP_CONTIG)

From: Michal Nazarewicz
Date: Wed Oct 04 2017 - 07:54:15 EST

On Tue, Oct 03 2017, Mike Kravetz wrote:
> At Plumbers this year, Guy Shattah and Christoph Lameter gave a presentation
> titled 'User space contiguous memory allocation for DMA' [1]. The slides
> point out the performance benefits of devices that can take advantage of
> larger physically contiguous areas.

Issue I have is that kind of memory needed may depend on a device. Some
may require contiguous blocks. Some may support scatter-gather. Some
may be behind IO-MMU and not care either way.

Furthermore, I feel dÃjà vu. Wasnât dmabuf supposed to address this

Best regards
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