Messages in this thread | | | Date | Mon, 4 May 2009 16:50:46 +0200 | From | Andi Kleen <> | Subject | Re: [PATCH] Implementation of the sendgroup() system call |
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On Mon, May 04, 2009 at 09:44:31AM -0400, Elad Lahav wrote: > >My guess it's more the copies than the calls? > It's a factor of both. This is why we also created the sendgroup() > implementation that uses a tight loop of in-kernel calls to sendmsg() > as a means for evaluating the cost of mode switches. It is definitely > not negligible (exact numbers depend on the size of the group and the > size of the payload, of course).
How much is non negligible in your case?
> > >It sounds like you want sendfile() for UDP. > Do you mean by having a per-recipient sendfile() call for the same > file? Leaving the cost of the system call aside, this solution does > not work well with the kind of real-time data that we've been working > with (live streaming, online games). You would have to write the > payload to the file as it is being generated and call sendfile() after > each such write.
You can mmap the file.
-Andi
-- ak@linux.intel.com -- Speaking for myself only.
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