Re: [Lse-tech] zerocopy pipe, new version

[Benjamin LaHaise]

On Tue, Jan 15, 2002 at 12:20:25PM -0500, Hubertus Franke wrote:
> Conclusion
> ----------
> Manfred Spraul's new zero copy patch showed a very good performance
> improvement for pipeflex as well as grep on both 2-way and 1-way.
> By adding our large pipe support, performance improvement up to
> 42% for pipeflex and 96% for grep benchmarks on 2-way systems.
> No significant different has been observed for lmbench on 1-way systems.
> The right way to configure the system than would be for UP and 1-way to
> set the buffer size by default to 4K while for the SMP larger pipe buffers
> should be encouraged.

Any conclusions are incomplete without mentioning the serious (30%+) 
degredation on UP systems under a good chunk of the benchmarks.  Such 
aspects of the patch make it unsuitable as is for both the mainstream 
and vendor kernels.

		-ben