Messages in this thread | | | Date | Tue, 30 Jan 2001 20:04:51 -0500 (EST) | From | jamal <> | Subject | Re: Still not sexy! (Re: sendfile+zerocopy: fairly sexy (nothing to do with ECN) |
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On Wed, 31 Jan 2001, Ingo Molnar wrote:
> > On Tue, 30 Jan 2001, jamal wrote: > > > Kernel | tput | sender-CPU | receiver-CPU | > > ------------------------------------------------- > > 2.4.0-pre3 | 99MB/s | 87% | 23% | > > NSF | | | | > > ------------------------------------------------- > > 2.4.0-pre3 | 68 | 8% | 8% | > > +ZC SF | MB/s | | | > > ------------------------------------------------- > > isnt the CPU utilization difference amazing? :-) >
With a caveat, sadly ;-> ttcp uses times() system call (or a diff of times() one at the beggining and another at the end). So the cpu measurements are not reflective.
> a couple of questions: > > - is this UDP or TCP based? (UDP i guess) > TCP
> - what wsize/rsize are you using? How do these requests look like on the > network, ie. are they suffieciently MTU-sized?
yes. writes vary from 8K->64K but not much difference over the long period of time.
> > - what happens if you run multiple instances of the testcode, does it > saturate bandwidth (or CPU)?
This is something of great interest. I havent tried it. I should. I suspect this would be where the value of the ZC changes will become evident.
cheers, jamal
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