On Tue, 3 May 2016 15:50:25 +0800 Wanpeng Li <kernellwp@xxxxxxxxx> wrote: > 2016-05-02 18:42 GMT+08:00 Christian Borntraeger <borntraeger@xxxxxxxxxx>: > [...] > > Some wakeups should not be considered a sucessful poll. For example on > > s390 I/O interrupts are usually floating, which means that _ALL_ CPUs > > would be considered runnable - letting all vCPUs poll all the time for > > transactional like workload, even if one vCPU would be enough. > > This can result in huge CPU usage for large guests. > > This patch lets architectures provide a way to qualify wakeups if they > > should be considered a good/bad wakeups in regard to polls. > > > > For s390 the implementation will fence of halt polling for anything but > > known good, single vCPU events. The s390 implementation for floating > > interrupts does a wakeup for one vCPU, but the interrupt will be delivered > > by whatever CPU comes first. To limit the halt polling we only mark the > > If the floating interrupt means that the 'CPU comes first' will > deliver the interrupt to all vCPUs? Floating interrupt on s390 means "deliver on any vcpu that matches the criteria, but only on one". -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
