Re: [linus:master] [mm] c0bff412e6: stress-ng.clone.ops_per_sec -2.9% regression

[David Hildenbrand <david@redhat.com>]

On 14.08.24 13:06, Mateusz Guzik wrote:
> On Wed, Aug 14, 2024 at 11:45 AM David Hildenbrand <david@redhat.com> wrote:
>>
>> On 14.08.24 06:10, Mateusz Guzik wrote:
>>> On Wed, Aug 14, 2024 at 5:02 AM Yin Fengwei <fengwei.yin@intel.com> wrote:
>>>>
>>>> On 8/13/24 03:14, Mateusz Guzik wrote:
>>>>> would you mind benchmarking the change which merely force-inlines _compund_page?
>>>>>
>>>>> https://lore.kernel.org/linux-mm/66c4fcc5-47f6-438c-a73a-3af6e19c3200@redhat.com/
>>>> This change can resolve the regression also:
>>>
>>> Great, thanks.
>>>
>>> David, I guess this means it would be fine to inline the entire thing
>>> at least from this bench standpoint. Given that this is your idea I
>>> guess you should do the needful(tm)? :)
>>
>> Testing
>>
>> diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
>> index 5769fe6e4950..25e25b34f4a0 100644
>> --- a/include/linux/page-flags.h
>> +++ b/include/linux/page-flags.h
>> @@ -235,7 +235,7 @@ static __always_inline int page_is_fake_head(const struct page *page)
>>           return page_fixed_fake_head(page) != page;
>>    }
>>
>> -static inline unsigned long _compound_head(const struct page *page)
>> +static __always_inline unsigned long _compound_head(const struct page *page)
>>    {
>>           unsigned long head = READ_ONCE(page->compound_head);
>>
>>
>> With a kernel-config based on something derived from Fedora
>> config-6.8.9-100.fc38.x86_64 for convenience with
>>
>> CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP=y
>>
>> add/remove: 15/14 grow/shrink: 79/87 up/down: 12836/-13917 (-1081)
> [snip]
>> Total: Before=32786363, After=32785282, chg -0.00%
> 
> I guess there should be no opposition then?
> 
> Given that this is your patch I presume you are going to see this through.

I was hoping that you could send an official patch, after all you did 
most of the work here.

> 
> I don't want any mention or cc on the patch, thanks for understanding :)

If I have to send it I will respect it.

-- 
Cheers,

David / dhildenb