Hello Marcelo & all, After checking the assembler code of clearbit with regard to the substition of task->processor, I added the last occurence of the variable in init_idle. Do You think the following patch is safe for inclusion into 2.4? It's been running for 3 days on this computer. Greetings, raY PS: Because of usage of prefetch in include/linux/list.h, the memory prefetch is triggered 137 times on my configuration... -- --------------------------------------------------------------- Rainer Keller Mail: Keller@hlrs.de Allmandring 30 WWW: http://www.hlrs.de/people/keller 70550 Stuttgart Tel. 0711 / 685 5858