On 2014-01-27 21:22, Andi Kleen wrote: > On Mon, Jan 27, 2014 at 08:14:06PM +0100, Jan Kiszka wrote: >> apic_icr_write and its users in smpboot.c were apparently written under >> the assumption that this code would only run during early boot. But >> nowadays we also execute it when onlining a CPU later on while the >> system is fully running. That will make wakeup_cpu_via_init_nmi and, >> thus, also native_apic_icr_write run in plain process context. If we >> migrate the caller to a different CPU at the wrong time or interrupt it >> and write to ICR/ICR2 to send unrelated IPIs, we can end up sending >> INIT, SIPI or NMIs to wrong CPUs. >> >> Fix this by disabling interrupts during the write to the ICR halves and >> disable preemption around waiting for ICR availability and using it. > > If you just want to disable migration use get_cpu()/put_cpu()
Fine with me if that is now preferred. Will that be the upstream way of -rt's migrate_disable()? Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
