Subject: Re: Testing newpipe
To: Manuel Bouyer <>
From: Jaromír <>
List: tech-kern
Date: 06/04/2001 13:44:33
Manuel Bouyer wrote:
> Do you know if hbench requires perl for this pipe tests ?
> I don't want to install perl on my older machines :)

I don't think it's necessary. I think simple test script like following
is okay:


for sz in 4096 8192 16384 32768 65536 131072 262144 524288; do
  /usr/pkg/bin/hbench/netbsd1.5U-i386/bw_pipe 10 $sz

Also, I found out that the PIPE_CHUNK code doesn't seem to be necessary
on -current kernels. Actually, I got better pipe performance for
128KB buffer size when PIPE_CHUNK was >128KB (256KB in my test), than
with PIPE_CHUNK at 64KB. My theory is that Jason's page coloring code
helped here. Even through PIPE_CHUNK is not needed for performance
reasons anymore, I'd still keep the chunking code to limit kva consumpsion
should someone use huge buffers for pipes.

Jaromir Dolecek <>
NetBSD - just plain best OS! -=*=- Got spare MCA cards or docs? Hand me them!