Hi, I recently upgraded one of our KVM servers from SL 6.0 to 6.1. Now (yesterday) the machine was under heavy I/O load. I investigated and saw that all virtual machines with CentOS 5.6 (we switched to SL just a few months ago) are writing hundreds of thousands of these messages to /var/log/messages:
Aug 8 13:15:20 infra kernel: : BUG: scheduling while atomic: swapper/0xffff0000/0 Aug 8 13:15:20 infra kernel: : Aug 8 13:15:20 infra kernel: : Call Trace: Aug 8 13:15:20 infra kernel: : [<ffffffff8006243d>] __sched_text_start+0x7d/0xbce Aug 8 13:15:20 infra kernel: : [<ffffffff8006bdb5>] default_idle+0x0/0x50 Aug 8 13:15:20 infra kernel: : [<ffffffff800494dd>] cpu_idle+0xb6/0xb8 Aug 8 13:15:20 infra kernel: : [<ffffffff80461807>] start_kernel+0x220/0x225 Aug 8 13:15:20 infra kernel: : [<ffffffff8046122f>] _sinittext+0x22f/0x236 Aug 8 13:15:20 infra kernel: : Now I'm not sure if this is a problem of the underlying CentOS kernel (that one was upgraded on july, 20th) or of SL 6.1 KVM (upgraded august, 1st). The SL 6.0/6.1 machines don't show this problem. The 5.6 machines didn't under SL 6.0. Right now I disabled the swap which seems to help, but this can of course only be a temporary solution. I also saw that RH released two minor releases of qemu-kvm that aren't yet in SL; would it make sense to try to compile the newest of them and update? If anyone knows something about this problem, any help is greatly appreciated. Regards, Torsten
