I was wrong. I built a new kernel from sources and performance is still very bad, with a load of 2500 minimum.
Also, venti, on this little machine, is a bit hungry for memory. venti...2010/0316 20:31:06 venti: conf.../boot/venti: mem 1,048,576 bcmem 140,753,578 icmem 211,130,368...httpd tcp!127.1!8000...init...icache 211,130,368 bytes = 3,298,912 entries; 16 scache sync...2010/0316 20:31:12 arenas01: indexing 430 clumps... announce tcp!127.1!17034...serving. fossil(#S/sdC0/fossil)...fsys: dialing venti at tcp!127.1!17034 This image formerly ran in 256M, now requires 512M, because venti footprint is 140+211+211 ... wait, how does it ever fit in 512 anyway. I think qemu changed too. An old kernel has the same problems. Not sure what is up here. but for now qemu on unongo 9.10 is useless for plan 9 from what I can see. ron