Messages in this thread | | | Date | Sun, 3 Sep 2000 22:49:32 +0200 | From | Jamie Lokier <> | Subject | Re: zero-copy TCP |
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Ingo Molnar wrote: > > At CERN we had a bunch of applications where this would be a win, data > > aquisition servers taking data in from on some custom hardware and > > sending out data over the wire on another card. You never really want > > to touch data in memory with the CPU but because of the lack of > > write() zero copy you end up having to do so. > > yep i agree - in this case a receivefile() implementation would be handy > (we are 100% ready in 2.4 to introduce it - from the pagecache and VFS > point of view, it's just not there yet), thus you could receivefile() your > data into a temporary file, and sendfile() it to the other card, without > ever touching data. This is faster than any zero-copy read()/write(), > because it can do things straight in the pagecache, without having to deal > with user-space page mappings.
It's not faster than card->card DMA, which falls out naturally from my zero-copy proposal :-)
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