Messages in this thread | | | Date | Thu, 16 Nov 2006 16:27:48 -0500 (EST) | Subject | Re: splice/vmsplice performance test results | From | David Miller <> |
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From: Jens Axboe <jens.axboe@oracle.com> Date: Thu, 16 Nov 2006 22:21:07 +0100
> On Thu, Nov 16 2006, David Miller wrote: > > From: "Jim Schutt" <jaschut@sandia.gov> > > Date: Thu, 16 Nov 2006 11:08:59 -0700 > > > > > Or is read+write really the fastest way to get data off a > > > socket and into a file? > > > > There is still no explicit TCP support for splice/vmsplice so things > > get copied around and most of the other advantaves of splice/vmplice > > aren't obtained either. So perhaps that explains your numbers. > > There should not be any copying for tcp send, at least no more than what > sendfile() did/does. Hmm?
That's true on send, correct.
> > Jens Axboe tries to get things working, and others have looked into it > > too, but adding TCP support is hard and for several reasons folks like > > Alexey Kuznetsov and Evgeniy Polyakov believe that sys_receivefile() > > is an interface much better suited for TCP receive. > > > > splice/vmsplice has a lot of state connected to a transaction, and > > perhaps that is part of why Evgeniy and Alexey have trouble wrapping > > their brains around an efficient implementation. > > I hope to try and see if I can help get some of that done, however I > need all the help I can get on the networking side. Not sure I > understand why it has to be so difficult, if we need to define a wrapper > container instead of passing down a pipe that is completely fine with > me. The networking code basically just needs to hang on to the > pipe_buffer and release it on ack for send, receive is somewhat more > involved (and I don't know enough about networking to voice any > half-intelligent opinion on that!). > > I would just consider it a damn shame if we cannot complete the splice > family and need to punt to something else for net receive.
I'm sure that the folks on netdev@vger.kernel.org are more than willing to give you a hand in this area :-) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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