Re: [PATCH 39 of 39] IB/ipath - use streaming copy in RDMA interrupthandler to reduce packet loss

[Rick Jones]

> If you bypass the L2 cache, it's pointless because the next
> agent (PCI controller, CPU thread, etc.) is going to need the
> data in the L2 cache.
>
> It's better in that kind of setup to eat the L2 cache miss overhead in
> memcpy since memcpy can usually prefetch and store buffer in order to
> absorb some of the L2 miss costs.

I thought that most PCI controllers (that is to say the things bridging 
PCI to the rest of the system) could do prefetching and/or that PCI-X 
(if not PCI, no idea about PCI-e) cards could issue multiple 
transactions anyway?

rick jones
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