Messages in this thread | | | From | Dan Williams <> | Subject | Re: [PATCH 2/2] ioatdma: add DMA_PRIVATE capabilities flag | Date | Thu, 27 Jun 2013 01:10:58 +0000 |
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On 6/26/13 4:55 PM, "Jon Mason" <jon.mason@intel.com> wrote: >Unfortunately, the dma_find_channel model does not led itself to >optimal usage of the available channels, as it seems to give out the >same channel. Adding some randomizer (or other way to spread the >channel selection over multiple channels) would be greatly >beneficial.
Right now the allocation scheme is per-cpu. If you have multiple submission contexts on different cpus it should use all available channels.
>Alternatively, adding an async_memcpy_mmio function (and perhaps some >minimal size to use the DMA engine) would provide a solution that >would work.
It¹s hard. The size is arch and use specific so it may be best to leave it up to the client.
>However, dma_find_channel should be sufficient to get NTB use of DMA >engines out for review. I'll clean it up and send it out shortly. >Thanks for the insight.
Cool, I¹ll take a look.
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