On Wed, 18 Apr 2018 10:19:32 +0000 "Wuzongyong (Euler Dept)" <cordius...@huawei.com> wrote:
> Hi, > > The qemu process will stuck when hot-add large size memory to the virtual > machine > with a device passtrhough. > We found it is too slow to pin and map pages in vfio_dma_do_map. > Is there any method to improve this process? At what size do you start to see problems? The time to map a section of memory should be directly proportional to the size. As the size is increased, it will take longer, but I don't know why you'd reach a point of not making forward progress. Is it actually stuck or is it just taking longer than you want? Using hugepages can certainly help, we still need to pin each PAGE_SIZE page within the hugepage, but we'll have larger contiguous regions and therefore call iommu_map() less frequently. Please share more data. Thanks, Alex _______________________________________________ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
