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

[Yu Zhao]

Hi Janosch and Oliver,

On Wed, Jul 17, 2024 at 1:57 AM Janosch Frank <frankja@xxxxxxxxxxxxx> wrote:
>
> 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.

Could you try the attached patch please? Thank you.

Attachment: hugetlb-fix.patch
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