Re: [linux-next:master] [mm/hugetlb_vmemmap] 875fa64577: vm-scalability.throughput -34.3% regression

[Janosch Frank]

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.