Re: [libvirt] 1GB huge pages and incompatible VM memory size

Hi All, Matt encountered the following issue when using 1GB huge pages with libvirt > This problem turned out to be entirely my fault because I didn't round > the VM's memory size to a 1G multiple, and the kernel tried to split > the VMA at the end of the region, triggering this code in the kernel > do_mbind() path, > > static int __split_vma(struct mm_struct *mm, struct vm_area_struct > *vma, > unsigned long addr, int new_below) > { > struct vm_area_struct *new; > int err; > > if (is_vm_hugetlb_page(vma) && (addr & > > ~(huge_page_mask(hstate_vma(vma))))) > return -EINVAL; > > I have no idea how a less fortunate developer without access to MM > experts would have figured this out. It's a shame virsh didn't error > out when I initially setup 1G hugepages with an incompatible VM memory > size. What do folks think about improving libvirt to warn or error when using a VM memory size that is not compatible with the host hugepage configuration?