From Bugzilla Helper: User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0) Description of problem: All of the interrupts are only being serviced on CPU0 only on SMP machines with XEON P4 (foster) processors inside. Intel has changed how interrupt delivery is handled with these processors. The old method of setting the APIC's to low- priority does not evenly distributed the interrupts among all CPU's. Version-Release number of selected component (if applicable): How reproducible: Always Steps to Reproduce: 1. Install RH7.2 on Dell SMP box with Xeon P4 processors. 2. check /proc/interrupts 3. frown Actual Results: /proc/interrupts will show 0 interrupts on all sources for any CPU other than CPU0. Expected Results: interrupt handling should be spread across more than one CPU. This is the behavior with the older Xeon processors (pre-foster) Additional info: Ingo is already aware of the issue and is working on a patch. This has been checked on RH kernel's 2.4.3, 2.4.9, 2.4.17
Fixed for the Advanced Server kernel