On 3 Sep 2000, Jes Sorensen 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.
Ingo
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This archive was generated by hypermail 2b29 : Thu Sep 07 2000 - 21:00:15 EST