On 7/9/24 07:11, kernel test robot wrote:
Hello, kernel test robot noticed a -34.3% regression of vm-scalability.throughput on: commit: 875fa64577da9bc8e9963ee14fef8433f20653e7 ("mm/hugetlb_vmemmap: fix race with speculative PFN walkers") https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master [still regression on linux-next/master 0b58e108042b0ed28a71cd7edf5175999955b233]
This has hit s390 huge page backed KVM guests as well. Our simple start/stop test case went from ~5 to over 50 seconds of runtime.