[Cbe-oss-dev] [RFC/PATCH] libspe2: use mapped dma registers to speed up proxy dma

[Gerhard Stenzel]

Kazunori Asayama <asayama at sm.sony.co.jp> wrote on 05/23/2007 10:57:51 AM:

> BTW, in this implementation, DMA proxy commands are always issued via
> direct access when SPE_MAP_PS is enabled. However, if DMA proxy
> commands are issued via direct access, we can't wait for completion of
> the DMAs via syscalls (poll/epoll). That means we can no longer wait
> for DMA completion by using libspe2 event API when SPE_MAP_PS is
> enabled. E.g., such a restriction makes it impossible to create
> applications which use event API to wait for PPE-initiated DMAs and do
> SPE-SPE communication via SNR. So I think we may have to introduce a
> new separate flag from SPE_MAP_PS to enable this optimized behavior,
> so that each application can choose preferable behavior.
>
> --
> (ASAYAMA Kazunori
>   (asayama at sm.sony.co.jp))
> t
How about "if (SPE_MAP_PS and not SPE_EVENTS_ENABLE)" for those cases?

Best regards,

Gerhard Stenzel, Linux on Cell Development, LTC
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