Sven-Thorsten Dietrich wrote: > On Mon, 2007-10-22 at 09:01 +0200, Back, Michael (ext) wrote: >> Hallo, >> I tried to run Windows XP with KVM on Linux 2.6.31.1 on a > > You mean .21.1 ? Classic typo I interestingly also did several times the last week. :) > >> AMD Opteron and on a Intel Xeon, on both it works fine! > >> After this test I patch the kernel with the current prempt-patch and on >> both it doesn't works! > > Did you try against 2.6.23-rt1. kvm in -rt1 is not usable. It's too old, lacking PREEMPT_NOTIFIER support, thus quickly triggering lockdep. > > If you must stay on .21, you might have some other issues with the AMD > and NUMA. > > At the very least, you will need to apply the attached patch from git > somehow, although this patch is against a new scheduler post 2.6.22, so > good luck :) <--snip--> Those patches are already mainline... :-> What you rather need are latest kvm patches, or - if building the kvm distribution out of tree - a patch to enabled CONFIG_PREEMPT_NOTIFIERS unconditionally: --- linux-2.6.23.1-rt/kernel/Kconfig.preempt.orig +++ linux-2.6.23.1-rt/kernel/Kconfig.preempt @@ -136,6 +136,7 @@ config PREEMPT_NOTIFIERS bool + default y config PREEMPT_BKL bool Still, I'm seeing oopses here (more precisely, lock validator complaints), but I need to re-test, better using kvm from git instead of kvm-48. Beyond this, I'm struggling to understand 300-400 us vm-exit latencies (over Intel VMX), which appear to be independent of the underlying system. See kvm-devel. Such latencies would limit the RT usability of kvm - unless you spent dedicated CPUs. Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux - To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
