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

["Marc Hartmayer" <mhartmay@linux.ibm.com>]

On Wed, Jul 17, 2024 at 09:44 AM -0600, Yu Zhao <yuzhao@google.com> wrote:
> On Wed, Jul 17, 2024 at 2:36 AM Yu Zhao <yuzhao@google.com> wrote:
>>
>> Hi Janosch and Oliver,
>>
>> On Wed, Jul 17, 2024 at 1:57 AM Janosch Frank <frankja@linux.ibm.com> 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.
>

Hi,

thanks a lot for the fix, it has fixed the problem on s390.

-- 
Kind regards / Beste Grüße
   Marc Hartmayer

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