On 02/12/19 10:10, Longpeng (Mike) wrote: > > Suppose there're two VMs: VM1 is bind to node-0 and calling vfio_pin_map_dma(), > VM2 is a migrate incoming VM which bind to node-1. We found the vm_start( QEMU > function) of VM2 will take too long occasionally, the reason is as follow. Which part of vfio_pin_map_dma is running? There is already a cond_resched in vfio_iommu_map. Perhaps you could add one to vfio_pin_pages_remote and/or use vfio_pgsize_bitmap to cap the number of pages that it returns. Paolo
