NUMA-Q breakage 7/7 preempt vs. printk bootstrap ordering
CONFIG_PREEMPT creates a bootstrap ordering issue as some implicit scheduling done in printk.c raises exceptions prior to the secondary cpus being prepared to handle them (seen as no vm86_info: BAD).
The workaround, enclosed below is not to use preempt on NUMA-Q.
Cheers,
Bill
===== arch/i386/config.in 1.40 vs edited =====
arch/i386/config.in +3 -1
@@ -165,7 +165,9 @@ define_bool CONFIG_X86_IO_APIC y fi else - bool 'Multiquad NUMA system' CONFIG_MULTIQUAD + if [ "$CONFIG_PREEMPT" != "y" ]; then + bool 'Multiquad NUMA system' CONFIG_MULTIQUAD + fi fi bool 'Machine Check Exception' CONFIG_X86_MCE