Re: [net-next PATCH 00/27] Add support for DMA writable pages being writable by the network stack

From: Jesper Dangaard Brouer
Date: Wed Oct 26 2016 - 11:45:54 EST


On Tue, 25 Oct 2016 11:36:48 -0400
Alexander Duyck <alexander.h.duyck@xxxxxxxxx> wrote:

> The first 22 patches in the set add support for the DMA attribute
> DMA_ATTR_SKIP_CPU_SYNC on multiple platforms/architectures. This is needed
> so that we can flag the calls to dma_map/unmap_page so that we do not
> invalidate cache lines that do not currently belong to the device. Instead
> we have to take care of this in the driver via a call to
> sync_single_range_for_cpu prior to freeing the Rx page.
>
> Patch 23 adds support for dma_map_page_attrs and dma_unmap_page_attrs so
> that we can unmap and map a page using the DMA_ATTR_SKIP_CPU_SYNC
> attribute.
>
> Patch 24 adds support for freeing a page that has multiple references being
> held by a single caller. This way we can free page fragments that were
> allocated by a given driver.
>
> The last 3 patches use these updates in the igb driver to allow for us to
> reimpelement the use of build_skb.
>
> My hope is to get the series accepted into the net-next tree as I have a
> number of other Intel drivers I could then begin updating once these
> patches are accepted.
>
> v1: Split out changes DMA_ERROR_CODE fix for swiotlb-xen
> Minor fixes based on issues found by kernel build bot
> Few minor changes for issues found on code review
> Added Acked-by for patches that were acked and not changed

I really appreciate you are doing this work Alex, thanks! And I do
think it fits into my page pool plans. Thanks!

--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
Author of http://www.iptv-analyzer.org
LinkedIn: http://www.linkedin.com/in/brouer